• Reference Type: Journal Article | Research Support, U.S. Gov't, P.H.S.
  Loog M and Morgan DO (2005) Cyclin specificity in the phosphorylation of cyclin-dependent kinase substrates. Nature 434(7029):104-8 PMID: 15744308
  • SGD Paper
  • DOI full text
  • PubMed
  • Reference supplement

  Cell-cycle events are controlled by cyclin-dependent kinases (CDKs), whose periodic activation is driven by cyclins. Different cyclins promote distinct cell-cycle events, but the molecular basis for these differences remains unclear. Here we compare the specificity of two budding yeast cyclins, the S-phase cyclin Clb5 and the M-phase cyclin Clb2, in the phosphorylation of 150 Cdk1 (Cdc28) substrates. About 24% of these proteins were phosphorylated more efficiently by Clb5-Cdk1 than Clb2-Cdk1. The Clb5-specific targets include several proteins (Sld2, Cdc6, Orc6, Mcm3 and Cdh1) involved in early S-phase events. Clb5 specificity depended on an interaction between a hydrophobic patch in Clb5 and a short sequence in the substrate (the RXL or Cy motif). Phosphorylation of Clb5-specific targets during S phase was reduced by replacing Clb5 with Clb2 or by mutating the substrate RXL motif, confirming the importance of Clb5 specificity in vivo. Although we did not identify any highly Clb2-specific substrates, we found that Clb2-Cdk1 possessed higher intrinsic kinase activity than Clb5-Cdk1, enabling efficient phosphorylation of a broad range of mitotic Cdk1 targets. Thus, Clb5 and Clb2 use distinct mechanisms to enhance the phosphorylation of S-phase and M-phase substrates.

Increase the total number of rows showing on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table.

Increase the total number of rows displayed on this page using the pull-down located below the table, or use the page scroll at the table's top right to browse through the table's pages; use the arrows to the right of a column header to sort by that column; to filter the table by a specific experiment type, type a keyword into the Filter box (for example, “microarray”); download this table as a .txt file using the Download button or click Analyze to further view and analyze the list of target genes using GO Term Finder, GO Slim Mapper, or SPELL.

Increase the total number of rows showing on this page by using the pull-down located below the table, or use the page scroll at the table's top right to browse through its pages; use the arrows to the right of a column header to sort by that column; filter the table using the "Filter" box at the top of the table.