Talk by Laura Tatjer Recordà about The yeast Ptc1 protein phosphatase – University of Copenhagen

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Talk by Laura Tatjer Recordà about The yeast Ptc1 protein phosphatase

Laura Tatjer Recordà has been invited by Sebastian Marquardt to visit CPSC on 27 October and will give a talk at 10.00-11.00 in room R660 and R661. The title of the talk is:

"The yeast Ptc1 protein phosphatase regulates a variety of cellular functions by targeting the Mkk1 kinase"

Abstract: The Saccharomyces cerevisiae type 2C protein phosphatase Ptc1 is required for a wide variety of cellular functions, although only a few cellular targets have been identified. A genetic screen in search of mutations in protein kinase encoding genes able to suppress multiple phenotypic traits caused by the ptc1 deletion yielded a single gene, MKK1, coding for a MAP kinase kinase (MAPKK) known to activate the cell wall integrity (CWI) Slt2 MAP kinase.

In contrast, mutation of the MKK1 paralog, MKK2, did not significantly alleviate the different ptc1 phenotypes. Deletion of MKK1 abolished the increased phosphorylation of Slt2 induced by the absence of Ptc1 both under basal or CWI pathway stimulatory conditions. We show that Ptc1 acts on both MAPKKs of the CWI pathway, although, only the Mkk1 kinase activity is essential for ptc1 mutants to display high Slt2 activation, and that Ptc1 is able to dephosphorylate Mkk1 in vitro.

Our results reveal the preeminent role of Mkk1 in signaling through the CWI pathway and strongly suggest that hyperactivation of Slt2 caused by deregulation of Mkk1 is at the basis of most of the phenotypic defects associated to lack of Ptc1 function