Premium
The protein kinase kin1, the fission yeast orthologue of mammalian MARK/PAR‐1, localises to new cell ends after mitosis and is important for bipolar growth
Author(s) -
Drewes Gerard,
Nurse Paul
Publication year - 2003
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(03)01080-9
Subject(s) - cytokinesis , mitosis , microbiology and biotechnology , schizosaccharomyces pombe , biology , schizosaccharomyces , cell cycle , interphase , cell division , cell growth , cell , yeast , saccharomyces cerevisiae , genetics
The kin1 protein kinase of the fission yeast Schizosaccharomyces pombe is a member of the PAR‐1/MARK (partitioning‐defective 1/microtubule‐associated protein/microtubule affinity‐regulating kinase) family important in eukaryotic cell polarity and cytoskeletal dynamics. We show here that kin1 plays a role in establishing the characteristic rod‐shaped morphology of fission yeast. Cells in which kin1 was deleted are viable but are impaired in growth, and are rounded at one end or both ends. They are monopolar because after mitosis they fail to activate bipolar growth, and are delayed in cytokinesis, resulting in a high proportion of septated cells often with multiple septa. This phenotype can be partially rescued by heterologous expression of human MARKs, which restore bipolar growth in most cells, but do not correct the delay in cytokinesis. Using chromosomal epitope tagging, we show that kin1p localises to the cell ends, except during mitosis when it disappears from cell ends. After mitosis, kin1p first reappears at the new cell end. Overexpression of kin1 results in a loss of polarity, with partially or fully rounded cells. From these results we suggest that kin1 is required to direct the growth machinery to the cell ends.