High impact information on PCL1

• The requirement of SWI4 for transcription appears to be direct: each gene contains sites similar to the CCBF-binding site; CCBF binds to the upstream region of HCS26 [1].
• In a/alpha diploid cells lacking CLN1 and CLN2, HCS26 is required for passage through G1 [2].
• Cell cycle control by a complex of the cyclin HCS26 (PCL1) and the kinase PHO85 [2].
• 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 [3].
• Additionally, PCL1 and BNI1, important regulators of yeast cell polarity, also suppress tif51A-1 temperature sensitivity [4].

Biological context of PCL1

• We propose that the G1 cyclins encoded by PCL1 and PCL2 positively regulate CDC42 or another morphogenesis promoting function [5].
• 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 [6].
• ORFD, an open reading frame adjacent to the CDC48 gene, is even more similar to HCS26 [7].

Associations of PCL1 with chemical compounds

• The SIT4 gene, which encodes a serine/threonine protein phosphatase, is required for the normal accumulation of CLN1, CLN2, and HCS26 RNAs during late G1 [8].

Physical interactions of PCL1

• The identification of Pcl1-interacting proteins that genetically interact with Cla4 may indicate a link between G1 progression and mitotic exit [9].

Other interactions of PCL1

• In addition, two other G1 cyclins, Pcl1 and Pcl2, associate with a second Cdk, Pho85, to contribute to Start [10].
• A similar sequence of events occurs at other SBF-regulated promoters, such as CLN1, CLN2, and PCL1 [11].
• A region of chromosome VII adjacent to SKI8 has a 453 amino acid open reading frame whose sequence has significant similarity to that of HCS26, a G1 cyclin [7].

References