Phosducin-like protein (PhLP), a regulator of G beta gamma function, interacts with the proteasomal protein SUG1.
Phosducin-like protein (PhLP) and phosducin are highly homologous proteins that interact with the beta gamma subunits of guanine nucleotide binding proteins. While phosducin has a well-characterized role in retinal signal transduction, PhLP function remains unclear. To further understand the function of PhLP, we have examined other potential protein:protein interactions with PhLP using the yeast two-hybrid system. PhLP was found to interact with a mouse homologue of the yeast SUG1, a subunit of the 26S proteasome which may also indirectly modulate transcription. This interaction was further confirmed by an in vitro binding assay and co-immunoprecipitation of the two proteins in overexpression studies. Inhibition of proteasome function by lactacystin led to accumulation of high molecular weight, ubiquitin-immunoreactive protein precipitated by PhLP antiserum. We suggest that PhLP/SUG1 interaction may target PhLP for proteasomal degradation.
Barhite
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Ernest Gallo Clinic and Research Center, Department of Neurology, University of California, San Francisco 94110, USA.
Thibault
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Miles
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D000251:Adenosine Triphosphatases; D000818:Animals; D015153:Blotting, Western; D019556:COS Cells; D002352:Carrier Proteins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D019976:Cloning, Organism; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D005910:Glioma; D005982:Glutathione Transferase; D006822:Hybrid Cells; D051379:Mice; D018832:Molecular Chaperones; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D009447:Neuroblastoma; D010447:Peptide Hydrolases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry / Q000378:metabolism*; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D015398:Signal Transduction; D014158:Transcription, Genetic; D014162:Transfection
D002352:Carrier Proteins; D005656:Fungal Proteins; D018832:Molecular Chaperones; D009419:Nerve Tissue Proteins; C498319:Pdcl protein, mouse; C498320:Pdcl protein, rat; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D005982:Glutathione Transferase; D010447:Peptide Hydrolases; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease; D000251:Adenosine Triphosphatases; D019204:GTP-Binding Proteins; C069670:RPT6 protein, S cerevisiae