High impact information on YCK1

• In Saccharomyces cerevisiae, the redundant YCK1 and YCK2 genes (Yeast Casein Kinase 1) are required for viability [1].
• These results support a model of glucose signaling in which glucose binding to the glucose sensors causes them to activate Yck1 in the cell membrane, which then phosphorylates Mth1 and Std1 bound to the cytoplasmic face of the glucose sensors, triggering their degradation and leading to the derepression of HXT gene expression [2].
• We present the following evidence that suggests that the glucose sensors are coupled to the membrane-associated protein kinase casein kinase I (Yck1) [2].
• Furthermore, phosphorylated Mth1, targeted by the casein kinases Yck1/2, binds to Grr1 [3].
• Akr1p appears to function in localizing Yck1p-Yck2p to the plasma membrane, a localization that depends on prenylation of C-terminal dicysteinyl motifs [4].

Biological context of YCK1

• In yeast, the products of the redundant YCK1 and YCK2 genes are together essential for cell viability [5].
• Despite partial colocalization with the Yck proteins, Hrr25p is unable to rescue the yck1 delta yck2 delta phenotype [6].
• Yck1p and Yck2p are peripheral plasma membrane proteins, and we report here that the localization of Yck2p within the membrane is dynamic through the cell cycle [5].
• Casein kinase I-like protein kinases encoded by YCK1 and YCK2 are required for yeast morphogenesis [7].
• The Saccharomyces casein kinase 1 isoforms encoded by the essential gene pair YCK1 and YCK2 control cell growth and morphogenesis and are linked to the endocytosis of several membrane proteins [8].

Anatomical context of YCK1

• Some Yck3p gene product was found associated with the plasma membrane, like Yck1p and Yck2p, but most confractionated with the nucleus, like another yeast casein kinase I isoform, Hrr25p [9].
• In the absence of functional Yck1p and Yck2p, Pdr5p is transported to the vacuole for degradation [10].

Associations of YCK1 with chemical compounds

• Mutations in both YCK1 and YCK2 affect this regulation, suggesting that H+-ATPase activity is modulated by glucose via a combination of a "down-regulating" casein kinase I activity and another, yet uncharacterized, "up-regulating" kinase activity [11].
• Our previous work found the two yeast plasma membrane-localized casein kinases Yck1p and Yck2p to be palmitoylated on C-terminal Cys-Cys sequences by the palmitoyl transferase Akr1p [12].

Other interactions of YCK1

• The subcellular distribution of three casein kinase I (CK1) homologs, encoded by the YCK1, YCK2, and HRR25 genes, has been determined in budding yeast through a combination of subcellular fractionation and immunofluorescence methods [6].
• The Delta320-413 deletion removes 18 Ser-Thr residues (possible YCK-independent phosphorylation sites) yet retains the 15 Ser-Thr residues of the Ste3p PEST-like ubiquitination-endocytosis signal [4].
• By contrast, two other previously characterized genes, the oxidative stress transcription factor gene, SKN7, and the yeast caesin protein kinase gene, YCK1, of S. cerevisiae do participate in this pathway [13].

Analytical, diagnostic and therapeutic context of YCK1

• Casein kinase I gamma subfamily. Molecular cloning, expression, and characterization of three mammalian isoforms and complementation of defects in the Saccharomyces cerevisiae YCK genes [14].

References