Phosphorylation of the Par-1 polarity kinase by protein kinase D regulates 14-3-3 binding and membrane association.
The Par-1 protein kinases are conserved from yeast to humans, where they function as key polarity determinants. The mammalian Par-1 family is comprised of 4 members (Par-1a, -b, -c, and -d). Previously, we demonstrated that atypical protein kinase C (aPKC) phosphorylates the Par-1 kinases on a conserved threonine residue (T595) to regulate localization and kinase activity. Here, we demonstrate that Par-1b is also regulated by another arm of the PKC pathway, one that involves novel PKCs (nPKC) and protein kinase D. Treatment of cells with the PKC activator phorbol-12-myristate-13-acetate (PMA) potently stimulated phosphorylation of Par-1b on serine 400 (S400), a residue that is conserved in all 4 mammalian Par-1 kinases as well as the fly ortholog. We demonstrate that PMA stimulates nPKC to activate PKD, which in turn directly phosphorylates Par-1b on S400 to positively regulate 14-3-3 binding and to negatively regulate membrane association. Thus, 2 arms of the PKC pathway regulate interactions between Par-1b and 14-3-3 proteins: one involving aPKC and the other nPKC/PKD.
Watkins
Janis L
JL
Department of Cell Biology and Physiology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
Lewandowski
Katherine T
KT
Meek
Sarah E M
SE
Storz
Peter
P
Toker
Alex
A
Piwnica-Worms
Helen
H
D048948:14-3-3 Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D016764:Cell Polarity; D004789:Enzyme Activation; D006801:Humans; D016297:Mutagenesis, Site-Directed; D010766:Phosphorylation; D011485:Protein Binding; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D048948:14-3-3 Proteins; C094670:MARK2 protein, human; C089212:protein kinase D; D017346:Protein Serine-Threonine Kinases; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate