Identification of the Gbeta5-RGS7 protein complex in the retina.
The G protein beta subunit G beta 5 deviates significantly from the four other members of the G beta family in amino acid sequence, unique expression pattern (only in the CNS), and cytosolic localization. To identify the members of the G beta 5-mediated signaling pathway, we purified the native protein complex containing G beta 5 from the cytosolic fraction of bovine retina. Analysis of the isolated complex revealed that G beta 5 is tightly associated with RGS7, a member of the superfamily of negative regulators of G protein signaling. This finding, for the first time, demonstrates an interaction between a G beta subunit and an RGS protein. G beta 5 was not detected in the outer segments of photoreceptor cells, suggesting that the cytosolic G beta 5-RGS7 complex is not directly involved in phototransduction.
Cabrera
J L
JL
Department of Molecular and Cellular Pharmacology, University of Miami School of Medicine, Florida 33136, USA.
de Freitas
F
F
Satpaev
D K
DK
Slepak
V Z
VZ
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D003600:Cytosol / Q000737:chemistry / Q000378:metabolism; D005136:Eye Proteins / Q000737:chemistry / Q000302:isolation & purification*; D044387:GTP-Binding Protein beta Subunits; D019204:GTP-Binding Proteins / Q000737:chemistry / Q000302:isolation & purification*; D020962:Heterotrimeric GTP-Binding Proteins; D066298:In Vitro Techniques; D046911:Macromolecular Substances; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification; D012160:Retina / Q000737:chemistry*; D012374:Rod Cell Outer Segment / Q000737:chemistry; D014785:Vision, Ocular
D005136:Eye Proteins; D044387:GTP-Binding Protein beta Subunits; D046911:Macromolecular Substances; D010446:Peptide Fragments; D019204:GTP-Binding Proteins; D020962:Heterotrimeric GTP-Binding Proteins