PMID- 10200251
OWN - NLM
STAT- MEDLINE
DCOM- 19990517
LR  - 20190501
IS  - 0027-8424 (Print)
IS  - 0027-8424 (Linking)
VI  - 96
IP  - 8
DP  - 1999 Apr 13
TI  - A mutation in the heterotrimeric stimulatory guanine nucleotide binding protein
      alpha-subunit with impaired receptor-mediated activation because of elevated
      GTPase activity.
PG  - 4268-72
AB  - It has been reported that substitution of Arg258, a residue within the GTPase
      domain of the heterotrimeric guanine nucleotide binding protein (G protein)
      alpha-subunit (alphas), to alanine (alphas-R258A) results in decreased activation
      by receptor or aluminum fluoride (AlF4-) and increased basal GDP release. Arg258 
      interacts with Gln170 in the helical domain, and, presumably, loss of this
      interaction between the GTPase and helical domain leads to more rapid GDP
      release, resulting in decreased activation by AlF4- and increased thermolability.
      In this study, we mutate Gln170 to alanine (alphas-Q170A) and demonstrate that
      this mutant, like alphas-R258A, has decreased activation by AlF4-, increased
      thermolability (both reversed in the presence of excess guanine nucleotide), and 
      an increased rate of GDP release. However, unlike alphas-R258A, alphas-Q170A does
      not have impaired receptor-mediated activation. Therefore, this interdomain
      interaction is critical to maintain normal guanine nucleotide binding (and hence 
      normal activation by AlF4-) but is not important for receptor-mediated
      activation. In single turnover GTPase assays, the catalytic rate for GTP
      hydrolysis of alphas-R258A was 14-fold higher than normal whereas that of
      alphas-Q170A was unaffected. Examination of the alphas crystal structure suggests
      that Arg258, through interactions with Glu50, might constrain the position of
      Arg201, a residue critical for catalyzing the GTPase reaction. This is an example
      of a mutation in a heterotrimeric G protein that results in an increased
      intrinsic GTPase activity and provides another mechanism by which G protein
      mutations can impair signal transduction.
FAU - Warner, D R
AU  - Warner DR
AD  - Membrane Biochemistry Section, Laboratory of Molecular and Cellular Neurobiology,
      National Institute of Neurological Disorders and Stroke, National Institutes of
      Health, Bethesda, MD 20892, USA. dwarner@helix.nih.gov
FAU - Weinstein, L S
AU  - Weinstein LS
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Proc Natl Acad Sci U S A
JT  - Proceedings of the National Academy of Sciences of the United States of America
JID - 7505876
RN  - 0 (Aluminum Compounds)
RN  - 0 (Macromolecular Substances)
RN  - 0 (Recombinant Proteins)
RN  - 0RH81L854J (Glutamine)
RN  - 146-91-8 (Guanosine Diphosphate)
RN  - 21340-02-3 (tetrafluoroaluminate)
RN  - 37589-80-3 (Guanosine 5'-O-(3-Thiotriphosphate))
RN  - 94ZLA3W45F (Arginine)
RN  - EC 3.6.1.- (GTP Phosphohydrolases)
RN  - EC 3.6.5.1 (GTP-Binding Protein alpha Subunits, Gs)
RN  - EC 4.6.1.1 (Adenylyl Cyclases)
RN  - L628TT009W (Isoproterenol)
RN  - Q80VPU408O (Fluorides)
SB  - IM
MH  - Adenylyl Cyclases/metabolism
MH  - Aluminum Compounds/pharmacology
MH  - Amino Acid Substitution
MH  - Animals
MH  - Arginine
MH  - Cattle
MH  - Cloning, Molecular
MH  - Escherichia coli
MH  - Fibrous Dysplasia, Polyostotic/genetics
MH  - Fluorides/pharmacology
MH  - GTP Phosphohydrolases/chemistry/*metabolism
MH  - GTP-Binding Protein alpha Subunits, Gs/chemistry/genetics/*metabolism
MH  - Glutamine
MH  - Guanosine 5'-O-(3-Thiotriphosphate)/metabolism/pharmacology
MH  - Guanosine Diphosphate/metabolism
MH  - Humans
MH  - Isoproterenol/pharmacology
MH  - Kinetics
MH  - Macromolecular Substances
MH  - Mutagenesis, Site-Directed
MH  - Polymerase Chain Reaction
MH  - Protein Structure, Secondary
MH  - Recombinant Proteins/metabolism
PMC - PMC16321
EDAT- 1999/04/14 00:00
MHDA- 1999/04/14 00:01
CRDT- 1999/04/14 00:00
PHST- 1999/04/14 00:00 [pubmed]
PHST- 1999/04/14 00:01 [medline]
PHST- 1999/04/14 00:00 [entrez]
AID - 10.1073/pnas.96.8.4268 [doi]
PST - ppublish
SO  - Proc Natl Acad Sci U S A. 1999 Apr 13;96(8):4268-72. doi: 10.1073/pnas.96.8.4268.