G Protein Pathways, Part B: G Proteins and their Regulators

850 Pages·2002·21.145 MB·English

by  Ravi Iyengar, John D. Hildebrandt (Eds.)

Contributors to Volume 344
Article numbers are in parentheses following the names of contributors.
Affiliations listed are current.
DLANOD M. HCTIVONAPA (44), Bayer -roC HTEBAZILE BUCK (36), Department of
poration, West Haven, Connecticut06516 ,ygolocamrahP Mount Sinai School of
,enicideM New ,kroY New York 10029
IKANI AZPIAZU (8), Department of Anesthe-
,ygolois Washington University Medical
,loohcS .tS Louis, Missouri 63110 MARK BUSMAN (41), Department of Cell
and Molecular Pharmacology and -repxE
ENIREHTAC H. BERLOT (19, 32), Depart- imental Therapeutics, Medical -revinU
ment of Cellular and Molecular Physio-
sity of South ,aniloraC ,notselrahC South
,ygol Yale University School of ,enicideM
aniloraC 29425
New Haven, Connecticut 06520
LEAHCIM L. BERNARD (37), Department ASEREHT M. AREV-ARERBAC (5), Depart-
of Pharmacology, Medical University ment of Molecular Pharmacology and
of South Carolina, Charleston, South ,yrtsimehcoiB Institute for ,ecneicsorueN
aniloraC 29403 Northwestern University, Chicago,
sionillI 11606
LAURIE BETTS (49), Department of Phar-
,ygolocam and UNC Biomolecular X-ray
Data Collection ,ytilicaF ehT ytisrevinU ASSENAV CHANG (18, 35), Department of
Anesthesiology, Washington University
of North Carolina at Chapel Hill, Chapel
,lliH North Carolina 27599 School of Medicine, .tS Louis, Missouri
63110
LUTZ REMUABNRIB (20), Department of
,ygoloisehtsenA School of Medicine, -inU
RETEP CAIDIHC (48), Department of Phar-
versity of ,ainrofilaC Los Angeles, Cali-
macology and ,ygolocixoT Faculty of
fornia 90095
Medicine and Dentistry, University of
MUILLIRT BLACKMER (30), Institute for nretseW Ontario, London, Ontario A6N
Neuroscience and Department of -oM 5C1, Canada
lecular Pharmacology and Biological
Chemistry, Northwestern University NEVETS R. SREDLIHC (3), Department
Medical School, ,ogacihC Illinois 60613 of Physiology and ,ygolocamrahP Cen-
ter for Investigative Neuroscience, Wake
GUYLAIN BOULAY (20), D~partement de
Forest University School of ,enicideM
Pharmacologie, Facultg de Mgdecine,
,melaS-notsniW North Carolina 27157
dtisrevinU de Sherbrooke, ,ekoorbrehS
,cebguQ Canada JIH 5N4
NEHPETS CHUNG (49), Ontario Cancer
GREG M. SREHTORB (49, 51), Ontario -naC
Institute/Amgen Institute, University of
cer Institute/Amgen Institute, University
,otnoroT Toronto, Ontario M5G 2C1,
of ,otnoroT ,otnoroT Ontario M5G ,1C2
adanaC
adanaC
EGROEG .P BROWN (25), Department of MARY J. IKSWOMSIC (11), Neurocrine Bio-
,ygolocamrahP Mount Sinai School of ,secneics ,detaroprocnI naS Diego, Cali-
Medicine, New ,kroY New York 10029 fornia 12129
xi
xii CONTRIBUTORS TO VOLUME 344
LANA A. COOK (16, 41), Department EMIR DUZIC (11), Millennium Pharmaceu-
of Pharmacology, Medical University ticals, Incorporated, Cambridge, Massa-
of South Carolina, Charleston, South chusetts 02139
Carolina 29425
ENIREHTAC A. DYE (20), Nina Ireland
YEHIA DAAKA (30), Department of Laboratory of Developmental Neurobiol-
,yregruS Duke University Medical ,retneC ,ygo Langley Porter Psychiatric Institute,
Durham, North Carolina 27710 University of California, San Francisco,
California 94143
E. J. DELL (30), Institute for Neuro-
science and Department of Molecular MARILYN GIST FARQUHAR (46), De-
Pharmacology and Biological Chemistry, partment of Cellular and Molecular
Northwestern University Medical School, Medicine, University of California, La
Chicago, Illinois 60613 Jolla, California 92093
LEAHCIM HTUMSSIERF (33), Institute of
KARYN M. DEPREE (5), Department of
Pharmacology, University of Vienna,
Pharmacology and Toxicology, West
A-1090 Vienna, Austria
Virginia University, Morgantown, West
ainigriV 26506 MARTHA E. GADD (48), Department of
Pharmacology, Emory University School
NAHTANOJ M. DERMOTT (21), Labora-
of Medicine, Atlanta, Georgia 30322
tory of Molecular Immunoregulation,
National Cancer Institute-Frederick Can- YNAFFIT NAYNUR NOSIRRAG (43, 44), De-
cer Research and Development ,retneC partment of Pharmacology, Yale Univer-
Frederick, Maryland 21702 sity School of Medicine, New Haven,
Connecticut 06536
Luc DE VRIES (46), Department of Cellu-
lar and Molecular Medicine, University N. GAUTAM (8, 18, 35), Departments of
of California, La Jolla, California 92093 Anesthesiology and Genetics, Washing-
ton University School of Medicine, .tS
N. NARAKESANAHD (21), Department of Louis, Missouri 63110
Biochemistry, Fels Institute for Can-
ELYK R. GEE (29), Molecular Probes, Inc.,
cer Research and Molecular Biology,
Eugene, Oregon 97402
Temple University School of Medicine,
Philadelphia, Pennsylvania 19140 ETTENNA GILCHRIST (4), Department of
Molecular Pharmacology and Biochem-
JANE DINGUS (13, 15, 16, 34), Depart-
istry, Institute for Neuroscience, North-
ment of Pharmacology, Medical Univer-
western University, Chicago, Illinois
sity of South Carolina, Charleston, South
11606
Carolina 29425
ALFRED G. GILMAN (47), Department
MARK D. DISTEFANO (18), Department of Pharmacology, University of Texas
of Chemistry, University of Minnesota, Southwestern Medical Center, Dallas,
Minneapolis, Minnesota 55455 Texas 75390
KIRNEH G. NAMLHOD (43, 44), Department NEHPETS G. GRABER (5), Department
of Biochemistry and Biophysics, Univer- of Pharmacology and Toxicology, West
sity of North Carolina at Chapel Hill Virginia University, Morgantown, West
Chapel Hill, North Carolina 27599 ainigriV 26506
SEDECREM DOSIL (7), Departamento de IDIEH E. HAMM (4, 5, 30, 41), De-
Bioqufmica y Biologica Molecular, Cam- partment of Pharmacology, Vanderbilt
pus Miguel de Unamuno, University of University Medical Center, Nashville,
Salamanca, 37007 Salamanca, Spain Tennessee 37232
CONTRIBUTORS TO VOLUME 344 xiii
WE! HE (50), Department of Biochem- HEE C. KANG (29), Molecular Probes, Inc.,
istry and Molecular Biology, Baylor Col- Eugene, Oregon 97402
lege of Medicine, Houston, Texas ,03077
and Department of Cell Biology, Memo- DANIEL R. KNAPP (34), Department of
rial Sloan-Kettering Cancer ,retneC New Pharmacology, Medical University of
,kroY New York 12001 South Carolina, Charleston, South Car-
olina 29425
NHOJ R. HEPLER (48), Department of Phar-
macology, Emory University School of JAMES B. KONOPKA (7), Department of
Medicine, Atlanta, Georgia 30322 Molecular Genetics and Microbiology,
State University of New York, Stony
JOHN D. HILDEBRANDT (10, 13, 15, 16,
Brook, New York 11794
34, 41), Department of Pharmacology,
Medical University of South Carolina, ANDREJS M. KRUMINS (47), Department
Charleston, South Carolina 29425 of Pharmacology, University of Texas
Southwestern Medical Center, Dallas,
YEE-KIN HO (9), Departments of Biochem-
Texas 75390
istry and Molecular Biology, University
of lllinois College of Medicine, Chicago,
OLIVER KUDLACEK (33), Institute of Phar-
Illinois 60612
macology, University of ,anneiV A-1090
GINGER A. HOFFMAN (43), Interdepartmen- ,anneiV Austria
tal Neuroscience Program, Yale Univer-
NEHPETS M. LANIER (10, 11, 37), Depart-
sity, New Haven, Connecticut 06536
ment of Pharmacology, Louisiana State
NIMGNOY HOU (35), Department of Anes- University Health Sciences Center, New
thesiology, Washington University School Orleans, Louisiana 70118
of Medicine, .tS Louis, Missouri 63110
DRAHEKKE LEBERER (6), Eukaryotic Ge-
XI-PING HUANG (22, 23), Department of netics Department, NRC Biotechnology
Pharmacology, Diabetes and Metabolic Research Institute, Montreal, Qugbec,
Diseases Research Center, University
Canada H4 P 2R2; and Department of Ex-
Medical Center, State University of New perimental Medicine, McGill ,ytisrevinU
,kroY Stony Brook, New York 11794
Montreal, Quebec, Canada H3A 1B1
RAVI IYENGAR (24, 25, 36), Department
REHWA HO LEE (9), Department of Anatomy
of Pharmacology, Mount Sinai School of
and Cell Biology, University of Califor-
Medicine, New ,kroY New York 10029
nia Los Angeles, School of Medicine and
GREGOR JANSEN (6), Eukaryotic Genet- Developmental Neurology Laboratory,
ics Department, NRC Biotechnology nareteV Administration Medical ,retneC
Research Institute, Montreal, Quebec, Sepulveda, California 91343
Canada H4P 2R2
ANLI LI (4), Institute for Neuroscience,
MEISHENG JIANG (20), Department of Northwestern University, Chicago, Illi-
Anesthesiology, School of Medicine, Uni- nois 11606
versity of California, Los Angeles, Cali-
fornia 90095 OLIVIER LICHTARGE (38), Department of
Molecular and Human Genetics, Pro-
RICHARD A. KAHN (14), Department of
gram ni Structural and Computational
Biochemistry, Emory University School of
Biology and Molecular Biophysics, Bay-
Medicine, Atlanta, Georgia 30322
lor Human Genome Sequencing ,retneC
TAMARA A. KALE (18), Department of Program ni Developmental Biology, Bay-
Chemistry, Washington University School lor College of Medicine, Houston, Texas
of Medicine, .tS Louis, Missouri 63110 03077
xiv CONTRIBUTORS TO VOLUME 344
JIE LIU (27), Metabolic Diseases ,hcnarB NAITSIRHC NANOFF (33), Institute of Phar-
National Institute of Diabetes, ,evitsegiD ,ygolocam University of ,anneiV A-1090
and Kidney Diseases, National Institutes ,anneiV Austria
of Health, Bethesda, Maryland 20892
RICHARD R. NEUBIG (29), Departments of
CHIENLING MA (11), OSI Pharmaceuti-
Pharmacology and Internal Medicine,
,slac Incorporated, ,nwotyrraT New kroY
University of Michigan, Ann Arbor,
19501
Michigan 48109
CRAIG C. MALBON (22, 23), Department of
,ygolocamrahP Diabetes and Metabolic JOHN K. NORTHUP (2), Laboratory of -leC
Diseases Research Center, University lular ,ygoloiB National Institute on Deaf-
Medical Center, State University of ness and Other Communication Dis-
New ,kroY Stony Brook, New kroY 11794 orders, National Institutes of Health,
,ellivkcoR Maryland 20850
DAVID R. MANNING (1), Department of
,ygolocamrahP University of -avlysnneP ANNE PHILIPPI (38), Department of -uceloM
nia School of Medicine, Philadelphia, lar and Human Genetics, Baylor egelloC
Pennsylvania 19104 of ,enicideM Houston, Texas 77030
ANGELES MARTiN-REQUERO (20), Centro
MARK R. PHILIPS (17), Departments of
de Investigaciones Biologicas, Consejo
Medicine and Cell Biology, New York
Superior de Investigaciones ,sacifitneiC
ytisrevinU School of ,enicideM New ,kroY
28006 Madrid, Spain
New York 10016
DYKE P. MCEWEN (29), Department of
,ygolocamrahP University of ,nagihciM IEUGRES VOPOP (45), AdvancedBiosystems,
Ann ,robrA Michigan 48109 ,sassanaM ainigriV 20110
WILLIAM E. MCINTIRE (13, 34), Depart-
ROTCIV REBOIS (2), Laboratory of -uceloM
ment of Pharmacology, Medical Uni-
lar and Cellular Neurobiology and Biol-
versity of South Carolina, ,notselrahC
,ygo National Institute of Neurological
South Carolina 29425; and Depart-
Diseases and Stroke, National Institutes
ment of ,ygolocamrahP University of -riV
of Health, Bethesda, Maryland 20892
ginia School of Medicine, ,ellivsettolrahC
ainigriV 22908
EITAN YNEVUER (30), Department of -loiB
PAMELA E. MENTESANA (7), Department ogical Chemistry, Weizmann Institute of
of Molecular Genetics and -loiborciM ,ecneicS Rehovot ,00167 Israel
,ygo State University of New ,kroY Stony
,koorB New York 11794 CATALINA RIBAS (10), Centro de Biol-
ogfa Molecular oreveS'" Ochoa" ( -C15C
DAVID MICHAELSON (17), Departments of UAM), Universidad Aut6noma de
Medicine and Cell Biology, New York Madrid, Cantoblanco, 28049 Madrid,
ytisrevinU School of ,enicideM New ,kroY niapS
New York 10016
JANET D. ROBISHAW (31), Weis Center
ANATEHCUS MUKHOPADHYAY (26), De-
for Research, Geisinger ,cinilC ,ellivnaD
partment of Biological Sciences, Purdue
ainavlysnneP 17822
,ytisrevinU West ,etteyafaL Indiana 47907
SUSANNE M. MUMBY (28), Department RAMON ROSAL (30), Division of -norivnE
of Pharmacology, University of saxeT mental Health Sciences, School of Public
Southwestern Medical Center, Dallas, Health, Columbia ,ytisrevinU New ,kroY
saxeT 75390 New York 23001
CONTRIBUTORS TO VOLUME 344 xv
SAMOHT A. TSIUQNESOR (22, 23), Depart- ARUAL J. SIM-SELLEY (3), Department of
ment of Pharmacology, Transgenic Mice Pharmacology and Toxicology and Insti-
,ytilicaF University Medical ,retneC State tute for Drug and Alcohol Studies, -riV
University of New ,kroY Stony Brook, New ginia Commonwealth University Medical
York 11794 College of ,ainigriV Richmond, ainigriV
23298
ELLIOTT M. ROSS (26, 42), Department
of Pharmacology, University of Texas IALOKIN .P SKIBA (30), Department
Southwestern Medical Center, Dallas, of Ophthalmology, Harvard Medical
Texas 75390 School, Howe Laboratories, Boston,
Massachusetts 02114
UWE HPLODUR (20), Institute of Pharma-
cology, University of Ziirich, CH-8057, ALAN .V SMRCKA (39), Department of
Pharmacology and Physiology, Univer-
Ziirich, Switzerland
sity of ,retsehcoR School of Medicine and
TARA NNA EROTNAS (24), Department of Dentistry, Rochester, New York 14642
Pharmacology, Mount Sinai School of
NAYRB E. SNOW (49, 51), Ontario Can-
Medicine, New York, New York 10029
cer Institate/Amgen Institute, University
OKIHOTOM SATO (10), First Department of ,otnoroT Toronto, Ontario M5G 2C1,
of lnternaI Medicine, Asahikawa Medical adanaC
,egelloC Hokkaido 078-8510, Japan
NHOJ KEDNOS (49), Departments of Bio-
NIVEK L. SCHEY (16, 34, 41), Department chemistry and Biophysics, and Phar-
of Pharmacology, Medical University of macology, Lineberger Comprehensive
South Carolina, Charleston, South Car- Cancer Center, The University of North
olina 29425 Carolina at Chapel Hill, Chapel Hill,
North Carolina 27599
PETER SCHUCK (2), Molecular Interac-
GNOSOAIX SONG (22), Department of Phar-
tions Resource, Division of Bioengineer-
macology, Diabetes and Metabolic Dis-
ing and Physical Science, Office of Re-
eases Research Center, University Medi-
search Services, National Institutes of
cal ,retneC State University of New ,kroY
Health, Bethesda, Maryland 20892
Stony Brook, New York 11794
MAILLIW REGNIDNIWHCS (31), Weis Center
WEHTAM E. SOWA (38), Program ni Struc-
for Research, Geisinger Clinic, Danville,
tural and Computational Biology and
Pennsylvania 17822
Molecular Biophysics, Department of
JAMIE K. SCOTT (39), Department of Biochemistry and Molecular Biology,
Molecular Biology and Biochemistry, Si- .W .M Keck Center for Computational
mon Fraser University, Burnaby, British Biology, Baylor College of Medicine,
Columbia, Canada A5V 1S6 Houston, Texas 77030
LEE R. RETKEHS (30), Department of Phar- NETSRAK REHCIPS (20), lnstitutfiir Phar-
makologie, Freie Universitiit Berlin,
macological and Physiological Sciences,
14195 Berlin, Germany
University of Chicago, Chicago, Illinois
60637 AYA ONOSEKAT (11), National Human
Genome Research Institute, National In-
DIVAD .P IKSVOREDIS (49, 51), Depart-
stitutes of Health, Bethesda, Maryland
ment of Pharmacology, UNC Neuro-
29802
science Center, and Lineberger Compre-
hensive Cancer Center, The University of WEI-JEN TANG (12), Ben May Institute
North Carolina at Chapel Hill Chapel for Cancer Research, ehT University of
Hill, North Carolina 27599 Chicago, Chicago, Illinois 60637
xvi CONTRIBUTORS TO VOLUME 344
NAUHCGNAIJ OAT (22), Department of LEE S. NIETSNIEW (27), Metabolic Diseases
Pharmacology, Diabetes and Metabolic Branch, National Institute of Diabetes,
Diseases Research Center, University Digestive, and Kidney Diseases, National
Medical Center, State University of New Institutes of Health, Bethesda, Maryland
,kroY Stony Brook, New York 11794 29802
NYWNORB S. TATUM (15), Department GEZHI WENG (40), Department of Pharma-
of Pharmacology, Medical University of ,ygoloc Mount Sinai School of Medicine,
South Carolina, Charleston, South Car- New ,kroY New York 10029
olina 29425
ERODOEHT G. WENSEL (50), Department
DAVID .Y THOMAS (6), Eukaryotic Ge-
of Biochemistry and Molecular ,ygoloiB
netics Department, NRC Biotechnology
Baylor College of Medicine, Houston,
Research Institute, Montreal, Qudbec,
Texas 77030
Canada H4P 2R2; and Departments of
Biology, and Anatomy and Cell Biol- MLOCLAM YAWETIHW (6), Eukaryotic Ge-
ogy, McGill University, Montreal, netics Department, NRC Biotechnology
Qudbec, Canada H3A 1B1 Research Institute, Montreal Qudbec,
TARITA O. THOMAS (5), Department of Canada H4P 2R2; and Department of
Molecular Pharmacology and Biochem- Biology, McGill University, Montreal,
istry, Institute for Neuroscience, North- Qudbec, Canada H3A 1B1
western University, Chicago, Illinois
LEAHCIM D. WILCOX (13, 16), Department
11606
of Pharmacology, Medical University
TUOW DANIEL TING (9), Departments of of South Carolina, Charleston, South
Biochemistry and Molecular Biology, Carolina 29425
University of Illinois College of Medicine,
Chicago, Illinois 60612 SAMOHT M. WILKIE (45), Department
of Pharmacology, University of Texas
YMMAT C. TUREK (18), Department of
Southwestern Medical Center, Dallas,
Chemistry, Washington University School
Texas 75390
of Medicine, .tS Louis, Missouri 63110
NADNIVOG NAHTANAYDIAV (15), Depart- ROLF T. WINDH (1), Adlolor Corporation,
ment of Pharmacology, Medical Univer- Malvern, Pennsylvania 19355
sity of South Carolina, Charleston, South
UYGNAUG WU (37), Department of Inter-
Carolina 29425
nal Medicine, University of Cincinnati,
NEGRUJ EWUAHNAV (5), Department of Cincinnati, Ohio 45267
Molecular Pharmacology and Biochem-
istry, Institute for Neuroscience, North- GNOHZ-IUHS NAY (12), Ben May Institute
western University, Chicago, Illinois for Cancer Research, The University of
11606 Chicago, Chicago, Illinois 60637
YRALLIH A. NAV HGRUBNEKLAV (14), DIVAD EWOY (45), Millennium Pharmaceu-
GlaxoSmithKline, King of Prussia, Penn- ticals, Cambridge, Massachusetts 02171
sylvania 19406
KAN UY (45), Department of Pharmacology,
UY-NEISH WANG (22, 23), Department of
University of Texas Southwestern Medi-
Physiology and Biophysics, University
cal Center, Dallas, Texas 75390
Medical Center, State University of New
,kroY Stony Brook, New York 11794 AUHUHS UY (27), Laboratory of Biochemi-
QIN WANG (31), Department of Pharma- cal Genetics, National Heart, Lung, and
cology, University of Michigan Medical Blood Institute, National Institutes of
School Ann Arbor, Michigan 48109 Health, Bethesda, Maryland 20892
Preface
The heterotrimeric G proteins are the central component of one of the primary
mechanisms used by eukaryotic cells to receive, interpret, and respond to extracel-
lular signals. Many of the basic concepts associated with the entire range of fields
collectively referred to in terms such as "signal transduction" originate from the pi-
oneering work of Sutherland, Krebs and Fischer, Rodbell and Gilman, Greengard,
and others on systems that are primary examples of G protein signaling pathways.
The study of these proteins has been and remains at the forefront of research on
cell signaling mechanisms. The G Protein Pathways volumes (343,344, and 345)
of Methods in Enzymology have come about as part of a continuing attempt to use
the methods developed in studying the G protein signaling pathways as a resource
both within this field and throughout the signal transduction field.
Several volumes of this series have been devoted in whole or in part to ap-
proaches for studying the heterotrimeric G proteins. Volumes 109 and 195 were
the earliest to devote substantial parts to G protein-mediated signaling systems.
In 1994 Volumes 237 and 238 comprehensively covered this field. The continued
growth, the ever increasing impact of this field, and the continued evolution of
approaches and questions generated by research related to G proteins have led
inevitably to the need for a new and comprehensive treatment of the approaches
used to study these proteins. Each volume of G Protein Pathways brings together
varied topics and approaches to this central theme.
Very early in the development of the concepts of G protein signaling mech-
anisms, Rodbell and Birnbaumer recognized at least three components of these
signaling systems. They compared them to a receiver, a transducer, and an am-
plifier. The receiver was the receptor for an extracellular signal. The transducer
referred to those mechanisms and components required for converting an extracel-
lular signal into an intracellular response. The amplifier was synonymous with the
effector enzymes that generate the beginning of the intracellular signal. Over the
years these ideas have evolved in many ways. We now know an immense amount
about the receptors and their great range of diversity. Through the work of Gilman,
along with his associates and contemporaries, the transducer component turned
out to be nearly synonymous with the heterotrimeric G proteins themselves. Nev-
ertheless, the complexity of this component of the system continues to become
more and more apparent with the recognition of the diversity of these proteins,
the many ways they interact, and the increasing number of regulatory influences
on their function. The key concepts associated with the effector enzymes, such as
adenylyl cyclase that produces the intracellular "second messenger" cAMP, have
iivx
XVlll PREFACE
been broadened substantially to include other enzymes, ion channels, and the com-
ponents of other signaling systems that form an interacting network of systems
inside cells.
The organization of Volumes 343,344, and 345 is still conveniently centered on
these three components of the G proteins signaling pathway: receptor, G protein,
and effector. The evolution of the field, however, inevitably left a mark on the form
of these volumes. So, for example, receptors in Volume 343 and G proteins in
Volume 344 no longer stand alone as individual components in these volumes, but
share space with other directly interacting proteins that influence their function. In
addition, Volume 345 addresses, more generally, effector mechanisms and forms
a bridge between the many different cell regulatory mechanisms that cooperate to
control cellular function. Thus, there are chapters that include methods related to
small GTP binding proteins, ion channels, gene regulation, and novel signaling
compounds.
As we learn more about G protein signaling systems, we acquire an ever
increasing appreciation of their complexity. In the previous volumes on G proteins
it was already evident that there were many different isoforms of each of the
three heterotrimeric G protein subunits. Initial analysis of the Human Genome
Project suggests some constraints on the number of members of these proteins with
27 ~ subunit isoforms, 315 subunits, and 31 y subunits. It is interesting that in recent
years we had nearly accounted for all or most of the/3 and y subunit isoforms, but
that there are nearly twice as many potential to subunits as the ones we currently
understand. These recent discoveries, along with the recognition of the existence of
between 600 and 700 G protein-coupled receptors in the human genome, may place
limits on the complexity of the G protein signaling system itself. These potential
limits, however, are balanced by the immense number of possible combinations
of interactions that can be generated from all these components, by the possible
variation of all of these proteins at levels after their genomic structure, and by our
continual discovery of additional interacting components of the system.
Perhaps one of the really substantial gains in our understanding of this sys-
tem since the earlier volumes is the increasing recognition of the role of acces-
sory proteins in G protein signaling pathways. Those proteins recognized nearly
20 years ago that work at the level of the receptor continue to grow and have a
prominent place in Volume 343. One of the real breakthroughs though has been the
rapid development of our knowledge of accessory proteins that interact with the G
proteins themselves. Prominent among these are the RGS (regulators of G protein
signaling) proteins that act as GTPase activating proteins for selective G protein
~t subunits. A fairly substantial section of these volumes is devoted to these proteins.
One apparent aside related to the RGS proteins though, is that as much as we have
rapidly learned about them, there is much more yet to be learned, because there is
wide variation in the structure of these proteins outside their G protein interaction
sites. These proteins likely have many different stories yet to be developed based
ECAFERP xix
on their interactions with the G proteins, perhaps mediating functions that we do
not yet know about. The RGS proteins are not the end of the interacting proteins
either, however, with the description of additional G protein-interacting proteins
such as the AGS (activators of G protein signaling) proteins. These are likely a
heterogeneous group of proteins with several different mechanisms of interaction
and roles in G protein signaling mechanisms.
The range of topics covered in these volumes turned out to be quite large. This
is a result of the wide range of approaches that creative scientists can develop
to gain an understanding of a complex and rapidly evolving field. There are sev-
eral chapters that provide a theoretical basis for the analysis and interpretation of
data, several chapters on the application of modeling techniques at several differ-
ent levels, and chapters on structural biology approaches, classical biochemical
techniques juxtaposed to protein engineering, molecular biology, gene targeting
strategies addressing physiological questions, and DNA array approaches to eval-
uating the effects of pathway activation. In all likelihood, the G protein signaling
field will continue to be one that moves at the forefront of scientific approaches to
studying events at the interface between biochemistry and molecular biology, on
the one hand, and physiology and cell biology, on the other. Thus, it is our hope that
these volumes will serve a scientific readership beyond those that study G proteins
per se, or even those that study cell signaling mechanisms. We would hope that the
approaches and techniques described here would hold relevance for those large
number of scientists involved in many different kinds of projects that address the
interface between the molecular/biochemical world and the cell/tissue/organism
world.
We owe a tremendous debt of gratitude to our colleagues who so readily con-
tributed chapters to these volumes. Truly, without their so willing participation this
work would not have evolved into as substantial and comprehensive a work as it
ultimately became. We would also like to thank Ms. Shirley Light for her support,
encouragement, and patience throughout this long process.
NHOJ D. TDNARBEDLIH
IVAR RAGNEYI
METHODS IN ENZYMOLOGY
EMULOV I. Preparation and Assay of Enzymes
Edited by SIDNEY .P KCIWOLOC DNA NATHAN O. NALPAK
EMULOV II. Preparation and Assay of Enzymes
Edited by SIDNEY .P KCIWOLOC DNA NATHAN O. NALPAK
EMULOV III. Preparation and Assay of Substrates
Edited by SIDNEY .P KCIWOLOC DNA NATHAN O. NALPAK
EMULOV IV. Special Techniques for the Enzymologist
Edited by SIDNEY .P KCIWOLOC DNA NATHAN O. NALPAK
EMULOV .V Preparation and Assay of Enzymes
Edited by SIDNEY .P KCIWOLOC DNA NATHAN O. NALPAK
EMULOV VI. Preparation and Assay of Enzymes (Continued)
Preparation and Assay of Substrates
Special Techniques
Edited by SIDNEY .P KCIWOLOC DNA NATHAN O. NALPAK
EMULOV VII. Cumulative Subject Index
Edited by SIDNEY .P KCIWOLOC DNA NATHAN O. NALPAK
EMULOV VIII. Complex Carbohydrates
Edited by HTEBAZILE E DLEFUEN DNA VICTOR GRUBSNIG
EMULOV IX. Carbohydrate Metabolism
Edited by WILLIS A. DOOW
EMULOV X. Oxidation and Phosphorylation
Edited by RONALD W. KOORBATSE DNA DRANYAM E. NAMLLUP
EMULOV XI. Enzyme Structure
Edited by C. H. W. HIRS
EMULOV XII. Nucleic Acids (Parts A and B)
Edited by ECNERWAL NAMSSORG DNA KIVIE EVADLOM
EMULOV XIII. Citric Acid Cycle
Edited by J. M. NIETSNEWOL
EMULOV XlW. Lipids
Edited by J. M. NIETSNEWOL
EMULOV .WX Steroids and Terpenoids
Edited by DNOMYAR B. NOTYALC
EMULOV XVI. Fast Reactions
Edited by HTENNEK KUSTIN
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