Molecular Cloning and Characterization of the G Protein γ Subunit of Cone Photoreceptors
| Autor: | Harvey K. Yamane, Henry K.W. Fong, Rehwa H. Lee, Bernard K.-K. Fung, Dean Bok, Olivia C. Ong, Kim B. Phan |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
DNA
Complementary genetic structures Protein subunit Molecular Sequence Data Protein Prenylation Biology Biochemistry GTP-Binding Proteins Complementary DNA Animals Amino Acid Sequence RNA Messenger Cloning Molecular Molecular Biology Peptide sequence Messenger RNA Base Sequence Sequence Homology Amino Acid cDNA library Immune Sera Cell Biology Immunohistochemistry Molecular biology Open reading frame Retinal Cone Photoreceptor Cells Cattle sense organs Transducin Visual phototransduction |
| Zdroj: | Journal of Biological Chemistry. 270:8495-8500 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.270.15.8495 |
| Popis: | The phototransduction process in cones has been proposed to involve a G protein that couples the signal from light-activated visual pigment to the effector cyclic GMP phosphodiesterase. Previously, we have identified and purified a G beta gamma complex composed of a G beta 3 isoform and an immunochemically distinct G gamma subunit (G gamma 8) from bovine retinal cones (Fung, B. K.-K., Lieberman, B. S., and Lee, R. H. (1992) J. Biol. Chem. 267, 24782-24788; Lee, R. H., Lieberman, B.S., Yamane, H. K., Bok, D., and Fung, B. K.-K. (1992a) J. Biol. Chem. 267, 24776-24781). Based on the partial amino acid sequence of this cone G gamma 8, we screened a bovine retinal cDNA library and isolated a cDNA clone encoding G gamma 8. The cDNA insert of this clone includes an open reading frame of 207 bases encoding a 69-amino acid protein. The predicted protein sequence of G gamma 8 shares a high degree of sequence identity (68%) with the G gamma (G gamma 1) subunit of rod transducin. Similar to rod G gamma 1, it terminates in a CIIS motif that is the site for post-translational modification by farnesylation. Messenger RNA for G gamma 8 is present at a high level in the retina and at a very low level in the lung, but is undetectable in other tissues. Immunostaining of bovine retinal sections with an antipeptide antibody against the N-terminal region of G gamma 8 further shows a differential localization of G gamma 8 to cones with a pattern indistinguishable from that of G beta 3. This finding suggests that G beta 3 gamma 8 is a component of cone transducin involved in cone phototransduction and color vision. |
| Databáze: | OpenAIRE |
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