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Adenyiyl Cyclase and G‐Proteins in Phytomonas
Author(s) -
FARBER MARISA D.,
MONTAGNA ANDREA E.,
PAVETO CRISTINA,
DOLLET MICHEL,
SANCHEZMORENO MANUEL,
OSUNA ANTONIO,
TORRES HECTOR N.,
FLAWIA MIRTHA M.
Publication year - 1995
Publication title -
journal of eukaryotic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 1066-5234
DOI - 10.1111/j.1550-7408.1995.tb01576.x
Subject(s) - cholera toxin , adenylyl cyclase , biology , adcy9 , gtp' , pertussis toxin , biochemistry , cyclase , membrane , enzyme , g protein , gs alpha subunit , adenylate kinase , adcy10 , microbiology and biotechnology , receptor
.Phytomonas sp. membranes have an adenylyl cyclase activity which is greater in the presence of Mn 2+ than with Mg 2+ . The Mg 2+ and Mn 2+ activity ratio varies from one membrane preparation to another, suggesting that the adenylyl cyclase has a variable activation state. A [ 35 S]GTP‐γ‐S‐binding activity with a Kd of 171 nM was detected in Phytomonas membranes. Incubation of these membranes with activated cholera or pertussis toxin and [adenylate 32 P]NAD + led to incorporation of radioactivity into bands of about 40–44 kDa. Crude membranes were electrophoresed on SDS‐polyacrylamide gels and analyzed, by Western blotting, with the 9188 anti‐α s antibody and the AS/7 antibody (anti‐α 1 , anti‐α i1 , anti‐α i2 ). These procedures resulted in the identification of polypeptides of approximately 40–44 kDa. Phytomonas adenylyl cyclase could be activated by treatment of membrane preparations with cholera toxin, in the presence of NAD + , while similar treatment with pertussis toxin did not affect this enzyme activity. These studies indicate that in Phytomonas , adenylyl cyclase activity is coupled to an unknown receptor entity through Gα s , proteins.