PMID- 9417126
OWN - NLM
STAT- MEDLINE
DCOM- 19980203
LR  - 20210209
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 273
IP  - 1
DP  - 1998 Jan 2
TI  - The G protein beta5 subunit interacts selectively with the Gq alpha subunit.
PG  - 636-44
AB  - The diversity in the heterotrimeric G protein alpha, beta, and gamma subunits may 
      allow selective protein-protein interactions and provide specificity for 
      signaling pathways. We examined the ability of five alpha subunits (alphai1, 
      alphai2, alphao, alphas, and alphaq) to associate with three beta subunits 
      (beta1, beta2, and beta5) dimerized to a gamma2 subunit containing an 
      amino-terminal hexahistidine-FLAG affinity tag (gamma2HF). Sf9 insect cells were 
      used to overexpress the recombinant proteins. The hexahistidine-FLAG sequence 
      does not hinder the function of the beta1gamma2HF dimer as it can be specifically 
      eluted from an alphai1-agarose column with GDP and AlF4-, and purified 
      beta1gamma2HF dimer stimulates type II adenylyl cyclase. The beta1gamma2HF and 
      beta2gamma2HF dimers immobilized on an anti-FLAG affinity column bound all five 
      alpha subunits tested, whereas the beta5gamma2HF dimer bound only alphaq. The 
      ability of other alpha subunits to compete with the alphaq subunit for binding to 
      the beta5gamma2HF dimer was tested. Addition of increasing amounts of purified, 
      recombinant alphai1 to the alphaq in a Sf9 cell extract did not decrease the 
      amount of alphaq bound to the beta5gamma2HF column. When G proteins in an extract 
      of brain membranes were activated with GDP and AlF4- and deactivated in the 
      presence of equal amounts of the beta1gamma2HF or beta5gamma2HF dimers, only 
      alphaq bound to the beta5gamma2HF dimer. The alphaq-beta5gamma2HF interaction on 
      the column was functional as GDP, and AlF4- specifically eluted alphaq from the 
      column. These results indicate that although the beta1 and beta2 subunits 
      interact with alpha subunits from the alphai, alphas, and alphaq families, the 
      structurally divergent beta5 subunit only interacts with alphaq.
FAU - Fletcher, J E
AU  - Fletcher JE
AD  - Department of Pharmacology, Health Sciences Center, University of Virginia, 
      Charlottesville, Virginia 22908, USA.
FAU - Lindorfer, M A
AU  - Lindorfer MA
FAU - DeFilippo, J M
AU  - DeFilippo JM
FAU - Yasuda, H
AU  - Yasuda H
FAU - Guilmard, M
AU  - Guilmard M
FAU - Garrison, J C
AU  - Garrison JC
LA  - eng
GR  - P01-CA-40042/CA/NCI NIH HHS/United States
GR  - R01-DK-19952/DK/NIDDK NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Recombinant Proteins)
RN  - EC 3.6.1.- (GTP-Binding Proteins)
SB  - IM
MH  - Animals
MH  - Baculoviridae/genetics
MH  - Brain/metabolism
MH  - Cattle
MH  - Cell Line
MH  - GTP-Binding Proteins/genetics/*metabolism
MH  - Protein Binding
MH  - Recombinant Proteins/genetics/metabolism
MH  - Spodoptera
EDAT- 1998/02/07 00:00
MHDA- 1998/02/07 00:01
CRDT- 1998/02/07 00:00
PHST- 1998/02/07 00:00 [pubmed]
PHST- 1998/02/07 00:01 [medline]
PHST- 1998/02/07 00:00 [entrez]
AID - S0021-9258(18)38626-5 [pii]
AID - 10.1074/jbc.273.1.636 [doi]
PST - ppublish
SO  - J Biol Chem. 1998 Jan 2;273(1):636-44. doi: 10.1074/jbc.273.1.636.