A surface on the G protein β-subunit involved in interactions with adenylyl cyclases Academic Article Article uri icon

Overview

MeSH Major

  • Asphyxia
  • Human Rights
  • Tear Gases
  • Violence

abstract

  • Receptor activation of heterotrimeric G proteins dissociates G alpha from the G betagamma complex, allowing both to regulate effectors. Little is known about the effector-interaction regions of G betagamma. We had used molecular modeling to dock a peptide encoding the region of residues 956-982 of adenylyl cyclase (AC) 2 onto Gbeta to identify residues on Gbeta that may interact with effectors. Based on predictions from the model, we synthesized peptides encoding sequences of residues 86-105 (Gbeta 86-105) and 115-135 (Gbeta 115-135) from Gbeta. The Gbeta 86-105 peptide inhibited G betagamma stimulation of AC2 and blocked G betagamma inhibition of AC1 and by itself inhibited calmodulin-stimulated AC1, thus displaying partial agonist activity. Substitution of Met-101 with Asn in this peptide resulted in the loss of both the inhibitory and partial agonist activities. Most activities of the Gbeta 115-135 peptide were similar to those of Gbeta 86-105 but Gbeta 115-135 was less efficacious in blocking G betagamma inhibition of AC1. Substitution of Tyr-124 with Val in the Gbeta 115-135 peptide diminished all of its activities. These results identify the region encoded by amino acids 84-143 of Gbeta as a surface that is involved in transmitting signals to effectors.

publication date

  • March 18, 1997

Research

keywords

  • Academic Article

Identity

Digital Object Identifier (DOI)

  • 10.1073/pnas.94.6.2711

PubMed ID

  • 9122261

Additional Document Info

start page

  • 2711

end page

  • 4

volume

  • 94

number

  • 6