Inhibitory and stimulatory G proteins of adenylate cyclase: cDNA and amino acid sequences of the alpha chains
| Autor: | Henry R. Bourne, Arthur D. Levinson, Kathleen A. Sullivan, Susan B. Masters, Yu-Chien Liao, Barry Beiderman, Fu-Hsiung Chang, Azadeh Alborzi |
|---|---|
| Rok vydání: | 1986 |
| Předmět: |
chemistry.chemical_classification
Adenosine Diphosphate Ribose Multidisciplinary Base Sequence Transcription Genetic G protein Protein primary structure DNA Peptide Elongation Factor Tu Biology Molecular biology Amino acid Biochemistry chemistry GTP-Binding Proteins G12/G13 alpha subunits Amino Acid Sequence Guanosine Triphosphate Transducin Peptide sequence EF-Tu Adenylyl Cyclases Research Article G alpha subunit |
| Zdroj: | Proceedings of the National Academy of Sciences. 83:6687-6691 |
| ISSN: | 1091-6490 0027-8424 |
| Popis: | The G protein family of signal transducers includes five heterotrimers, which are most clearly distinguished by their different alpha chains. The family includes Gs and Gi, the stimulatory and inhibitory GTP-binding regulators of adenylate cyclase; Go, a protein of unknown function abundant in brain; and transducin 1 and transducin 2, proteins involved in retinal phototransduction. Using a bovine alpha t1 cDNA as a hybridization probe, we have isolated mouse cDNAs that encode alpha chains of two G proteins. One encodes a polypeptide of 377 amino acids (Mr 43,856), identified as alpha s because it specifically fails to hybridize with any transcript in an alpha s-deficient S49 mouse lymphoma mutant, cyc-; the other encodes a polypeptide of 355 amino acids (Mr 40,482), presumed to be alpha i. These alpha chains and those of the retinal transducins exhibit impressive sequence homology. Of the four, alpha t1 and alpha t2 are most alike (81% identical amino acid residues), whereas the presumptive alpha i is more similar than alpha s to alpha t1 (63% vs. 38% identical residues). Sequence homologies with p21ras and elongation factor Tu identify regions of the alpha chains that form the site for GTP binding and hydrolysis. Further comparison of the alpha-chain sequences suggests additional regions that may contribute to interactions with beta gamma subunits and the receptor and effector components of different signal transduction systems. |
| Databáze: | OpenAIRE |
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