High impact information on PCL2

• PCL2 interacted with the cdk PHO85 in vivo and in vitro and formed a kinase complex that had G1-periodic activity [1].
• The PCL2 (ORFD)-PHO85 cyclin-dependent kinase complex: a cell cycle regulator in yeast [1].
• Gene expression assays and chromatin immunoprecipitation experiments revealed Slt2-dependent recruitment of SBF to the promoters of the G(1) cyclins PCL1 and PCL2 after activation of the Slt2-MAPK pathway [2].
• One of these genes, CLG1, was previously suggested to encode a cyclin, based on the protein's sequence homology to Pcl1 and Pcl2 [3].
• Using chymotryptic phosphopeptide mapping, we have identified the sites on which Rvs167p is phosphorylated in vitro by Pcl2p-Pho85p [4].

Biological context of PCL2

• We propose that the G1 cyclins encoded by PCL1 and PCL2 positively regulate CDC42 or another morphogenesis promoting function [5].
• PCL2 is already known to be expressed in late G1 and we find that, in addition, it is also regulated by Swi5 in telophase [6].
• The expression of PCL2 and PCL9 at this stage of the cell cycle implies a role for the Pho85 Cdk at the end of mitosis [6].
• This pattern of regulation is different from PCL1 and PCL2, which are expressed later in G1 phase and are regulated primarily by the transcription factor SBF [7].

Physical interactions of PCL2

• We identified a gene with a Swi5-binding site in the promoter that encoded a protein with high homology to Pcl2, a cyclin-like protein that associates with the Cdk Pho85 [6].

Other interactions of PCL2

• In contrast, deletion of PCL2, the closest relative of PCL9, had no effect on the budding pattern [7].
• Fus3p and Kss1p together increase the expression of CLN3 and PCL2 genes that promote budding, and Kss1p inhibits the MAP kinase cascade [8].
• Previous work has shown that Rvs167p can be phosphorylated in vitro by the cyclin-dependent kinase Pho85p complexed with its cyclin Pcl2p [4].

Analytical, diagnostic and therapeutic context of PCL2

• We performed both biochemical and genetic tests to discover the biological significance of the interaction between Pcl2 and Swi5 seen in the two-hybrid assay [9].

References