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Activated G sα but not G iα prevents the thermal inactivation of adenylyl cyclase in plasma membranes derived from S49 lymphoma cells
Author(s) -
Kvapil Petr,
Novotny Jiri,
Ransnäs Lennart A.
Publication year - 1994
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(94)80557-1
Subject(s) - adenylyl cyclase , membrane , chemistry , lymphoma , microbiology and biotechnology , biology , biochemistry , immunology , enzyme
The thermal inactivation of adenylyl cyclase was studied in plasma membranes isolated from wild‐type and the mutant cell strain cyc − of S49 lymphoma. The half‐life of adenylyl cyclase activity at 30°C was decreased from 14.2 min to 3.4 min by the presence of detergents. ATP as well as forskolin prevented the adenylyl cyclase inactivation in a dose‐response manner independent of the utilized type of cell membranes. Activation of G‐proteins by GTPγS or by AlF − 4 in wild‐type membranes but not in cyc − membranes partially prevented adenylyl cyclase inactivation. Adenylyl cyclase activity in cyc − membranes was preserved in the presence of GTPγS or AlF 4 from the observed detergent‐induced inactivation by complementation of these membranes with an extract from wild‐type membranes. ADP‐ribosylation of G iα in a cyc − membranes did not influence the kinetics of the inactivation process of adenylyl cyclase, whereas ADP‐ribosylated G sα , protein protected adenylyl cyclase more effectively than non‐ribosylated G sα in wild‐type plasma membranes when GTP was used as an activator.