Ste20-kinase-dependent TEDS-site phosphorylation modulates the dynamic localisation and endocytic function of the fission yeast class I myosin, Myo1.
Type I myosins are monomeric motors involved in a range of motile and sensory activities in different cell types. In simple unicellular eukaryotes, motor activity of class I myosins is regulated by phosphorylation of a conserved 'TEDS site' residue within the motor domain. The mechanism by which this phosphorylation event affects the cellular function of each myosin I remains unclear. The fission yeast myosin I, Myo1, activates Arp2/3-dependent polymerisation of cortical actin patches and also regulates endocytosis. Using mutants and Myo1-specific antibodies, we show that the phosphorylation of the Myo1 TEDS site (serine 361) plays a crucial role in regulating this protein's dynamic localisation and cellular function. We conclude that although phosphorylation of serine 361 does not affect the ability of this motor protein to promote actin polymerisation, it is required for Myo1 to recruit to sites of endocytosis and function during this process.
Attanapola
Sheran L
SL
Cell and Developmental Biology Group, School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, UK.
Alexander
Christopher J
CJ
Mulvihill
Daniel P
DP
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D004705:Endocytosis; D008969:Molecular Sequence Data; D018995:Myosin Heavy Chains / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases; D021381:Protein Transport; D012568:Schizosaccharomyces / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D054462:p21-Activated Kinases / Q000235:genetics / Q000378:metabolism*
D002352:Carrier Proteins; D029702:Schizosaccharomyces pombe Proteins; C491828:myo1 protein, S pombe; C500976:Nak1 protein, S pombe; D017346:Protein Serine-Threonine Kinases; D054462:p21-Activated Kinases; C094341:shk1 protein, S pombe; D018995:Myosin Heavy Chains