Identification of Rgp1p, a novel Golgi recycling factor, as a protein required for efficient localization of yeast casein kinase 1 to the plasma membrane.
The Yck1p and Yck2p casein kinase 1 isoforms in yeast are essential peripheral plasma membrane-associated protein kinases with roles in endocytosis, cellular morphogenesis and cytokinesis. The membrane targeting of these cytoplasmically oriented protein kinases requires normal secretory pathway function, but specific targeting factors have not been identified. To learn more about Yckp targeting, we characterized mutations that cause synthetic lethality with impairment of Yck function. We report here that these include mutations in two gene products that function in protein trafficking. One of these is the previously described t-SNARE Tlg2p, which participates in recycling of proteins to the Golgi. The other is a previously uncharacterized protein, Rgp1p, which appears to have a similar function. Loss of either Tlg2p or Rgp1p causes inefficient localization of Yck2p, suggesting that its transport may be directed, in part, by a targeting factor that must be recycled back to the Golgi.
Panek
H R
HR
Department of Biochemistry, Louisiana State University Health Science Center, Shreveport, LA 71130, USA.
Conibear
E
E
Bryan
J D
JD
Colvin
R T
RT
Goshorn
C D
CD
Robinson
L C
LC
D015415:Biomarkers; D002268:Carboxypeptidases / Q000378:metabolism; D047388:Casein Kinases; D043402:Cathepsin A; D002462:Cell Membrane / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D020662:Guanine Nucleotide Exchange Factors; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins; D043484:Proprotein Convertases; D011494:Protein Kinases / Q000378:metabolism*; D050765:Qa-SNARE Proteins; D050683:R-SNARE Proteins; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D013381:Subtilisins / Q000378:metabolism; D014617:Vacuoles / Q000378:metabolism
D015415:Biomarkers; D005656:Fungal Proteins; D020662:Guanine Nucleotide Exchange Factors; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D050765:Qa-SNARE Proteins; D050683:R-SNARE Proteins; C421763:RGP1 protein, S cerevisiae; C083241:SNC1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C066755:Sec7 guanine nucleotide exchange factors; C112252:TLG2 protein, S cerevisiae; D011494:Protein Kinases; D047388:Casein Kinases; D002268:Carboxypeptidases; D043402:Cathepsin A; D043484:Proprotein Convertases; D013381:Subtilisins; C058751:KEX2 protein, S cerevisiae