High impact information on RIC1

• We have shown previously that activation of Ypt6p depends on its exchange factor, Ric1p-Rgp1p, a peripheral membrane protein complex restricted to the Golgi [1].
• Ric1p largely colocalizes with the late Golgi marker Sec7p [2].
• We infer that the Ric1p-Rgp1p complex serves to activate Ypt6p on Golgi membranes by nucleotide exchange, and that this is required for efficient fusion of endosome-derived vesicles with the Golgi [2].
• Cells carrying a deletion of RIC1 (ric1Delta) mislocalize TGN membrane proteins Kex2p and Vps10p to the vacuole [3].
• Ric1p and the Ypt6p GTPase function in a common pathway required for localization of trans-Golgi network membrane proteins [3].

Biological context of RIC1

• The wild type gene, termed RIC1 (for ribosome control) was cloned by complementation of the temperature-sensitive phenotype from a genomic DNA library based on the CEN plasmid [4].

Anatomical context of RIC1

• RIC1, a novel gene required for ribosome synthesis in Saccharomyces cerevisiae [4].

Other interactions of RIC1

• Ypt6p shows a similar distribution, but this is altered when RIC1 or RGP1 is mutated [2].
• Like rcy1Delta, cells lacking the Rab-GTPase Ypt6p or its heterodimeric GEFs Rgp1p and Ric1p are unable to recycle the v-SNARE Snc1p [5].

References