A conserved non-canonical docking mechanism regulates the binding of dual specificity phosphatases to cell integrity mitogen-activated protein kinases (MAPKs) in budding and fission yeasts.
Dual-specificity MAPK phosphatases (MKPs) are essential for the negative regulation of MAPK pathways. Similar to other MAPK-interacting proteins, most MKPs bind MAPKs through specific docking domains known as D-motifs. However, we found that the Saccharomyces cerevisiae MKP Msg5 binds the MAPK Slt2 within the cell wall integrity (CWI) pathway through a distinct motif (IYT). Here, we demonstrate that the IYT motif mediates binding of the Msg5 paralogue Sdp1 to Slt2 as well as of the MKP Pmp1 to its CWI MAPK counterpart Pmk1 in the evolutionarily distant yeast Schizosaccharomyces pombe. As a consequence, removal of the IYT site in Msg5, Sdp1 and Pmp1 reduces MAPK trapping caused by the overexpression of catalytically inactive versions of these phosphatases. Accordingly, an intact IYT site is necessary for inactive Sdp1 to prevent nuclear accumulation of Slt2. We also show that both Ile and Tyr but not Thr are essential for the functionality of the IYT motif. These results provide mechanistic insight into MKP-MAPK interplay and stress the relevance of this conserved non-canonical docking site in the regulation of the CWI pathway in fungi.
Departamento de Microbiología II, Facultad de Farmacia, Universidad Complutense de Madrid, and Instituto Ramón y Cajal de Investigaciones Sanitarias (IRYCIS), Madrid, Spain.
Almudena
A
Sacristán-Reviriego
Yeast Physiology Group, Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, Murcia, Spain.
Marisa
M
Madrid
Yeast Physiology Group, Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, Murcia, Spain.
José
J
Cansado
Departamento de Microbiología II, Facultad de Farmacia, Universidad Complutense de Madrid, and Instituto Ramón y Cajal de Investigaciones Sanitarias (IRYCIS), Madrid, Spain.
Humberto
H
Martín
Departamento de Microbiología II, Facultad de Farmacia, Universidad Complutense de Madrid, and Instituto Ramón y Cajal de Investigaciones Sanitarias (IRYCIS), Madrid, Spain.
María
M
Molina
D020816:Amino Acid Motifs / Q000235:genetics; D000595:Amino Acid Sequence; D001665:Binding Sites / Q000235:genetics; D054638:Dual Specificity Phosphatase 1 / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D054637:Dual-Specificity Phosphatases / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D005434:Flow Cytometry; D015151:Immunoblotting; D008856:Microscopy, Fluorescence; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D010766:Phosphorylation; D010802:Phylogeny; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
D029701:Saccharomyces cerevisiae Proteins; D029702:Schizosaccharomyces pombe Proteins; D020928:Mitogen-Activated Protein Kinases; C516338:Pmk1 protein, S pombe; C072724:SLT2 protein, S cerevisiae; C110459:Pmp1 protein, S pombe; D054638:Dual Specificity Phosphatase 1; D054637:Dual-Specificity Phosphatases; C467054:SDP1 protein, S cerevisiae