Dissecting the M Phase-specific Phosphorylation of Serine-Proline or Threonine-Proline Motifs

作者：Wu, Chuan Fen; Wang, Ruoning; Liang, Qianjin; Liang, Jianjiao; Li, Wenke; Jung, Sung Yun; Qin, Jun; Lin, Sue-Hwa; Kuang, Jian^*

来源：Molecular Biology of the Cell, 2010, 21(9): 1470-1481.

DOI：10.1091/mbc.E09-06-0486

• MATURATION-PROMOTING FACTOR
• MONOCLONAL-ANTIBODY MPM-2
• XENOPUS-OOCYTE MATURATION
• MYELIN BASIC-PROTEIN
• SUBSTRATE RECOGNITION
• CELL-CYCLE
• SIGNAL-TRANSDUCTION
• CYTOSTATIC FACTOR
• METAPHASE ARREST
• PRIMARY SEQUENCE

M phase induction in eukaryotic cell cycles is associated with a burst of protein phosphorylation, primarily at serine or threonine followed by proline (S/TP motif). The mitotic phosphoprotein antibody MPM-2 recognizes a significant subset of mitotically phosphorylated S/TP motifs; however, the required surrounding sequences of and the key kinases that phosphorylate these S/TP motifs remain to be determined. By mapping the mitotic MPM-2 epitopes in Xenopus Cdc25C and characterizing the mitotic MPM-2 epitope kinases in Xenopus oocytes and egg extracts, we have determined that phosphorylation of TP motifs that are surrounded by hydrophobic residues at both -1 and +1 positions plays a dominant role in M phase-associated burst of MPM-2 reactivity. Although mitotic Cdk and MAPK may phosphorylate subsets of these motifs that have a basic residue at the +2 position and a proline residue at the -2 position, respectively, the majority of these motifs that are preferentially phosphorylated in mitosis do not have these features. The M phase-associated burst of MPM-2 reactivity can be induced in Xenopus oocytes and egg extracts in the absence of MAPK or Cdc2 activity. These findings indicate that the M phase-associated burst of MPM-2 reactivity represents a novel type of protein phosphorylation in mitotic regulation.

• 出版日期2010-5-1
• 单位北京师范大学