Work

Requirement for intramolecular domain interaction in activation of G protein alpha subunit by aluminum fluoride and GDP but not by GTP gamma S.

Year: 1994

Type: article

Abstract: An ion-counterion interaction between the lysine of the NKXD motif in the GTPase domain and an aspartate in the inserted helical domain of alpha subunits of heterotrimeric G proteins, Lys-278 and Asp-158, respectively, of Gs alpha is shown to be essential for activation by AlF4- and partially so for interaction with beta gamma dimers and activation by GTP and receptor. However, this domain interaction is not required for activation by the non-hydrolyzable analog guanosine 5'-3-O-(thio)triphosphate. Proximity of the helical domain to the GTPase domain is thus involved in the fundamental inactive-->active transition of the protein in a way that further distinguishes alpha subunits of heterotrimeric G proteins from ras and ras-like GTPases that lack helical domains and are neither activated by AlF4- nor combine with beta gamma dimers.

Source: Journal of Biological Chemistry

DOI: 10.1016/s0021-9258(18)43878-1

Authors: J Codina, L Birnbaumer

Language: English

Topic: Receptor Mechanisms and Signaling

Subfield: Molecular Biology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: hybrid

Estimated APC paid: $3,430

Funders: National Institutes of Health, National Heart, Lung, and Blood Institute, National Institute of Diabetes and Digestive and Kidney Diseases

Awards: CAPACITATIVE CALCIUM ENTRY (CCE) MECHANISMS, G5269719099, G972493160