GSK3 and Polo-like kinase regulate ADAM13 function during cranial neural crest cell migration.
Bottom Line: We further show that inhibition of either kinase blocks CNC migration and that the respective phosphomimetic forms of ADAM13 can rescue these inhibitions.However, these phosphorylations are not required for ADAM13 proteolysis of its substrates, γ-secretase cleavage, or nuclear translocation of its cytoplasmic domain.Of significance, migration of the CNC can be restored in the absence of Plk phosphorylation by expression of calpain-8a, pointing to impaired nuclear activity of ADAM13.
Affiliation: Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA 01003.Show MeSH
Related in: MedlinePlus
Mentions: To determine the effect of GSK3 and Plk phosphorylations on ADAM13 proteolytic activity, we tested the ability of the nonphosphorylatable mutants to cleave substrates both in vitro and in vivo. When cotransfected with the protocadherin PAPC in Cos-7 cells, both nonphosphorylatable ADAM13 variants Plk/A and Gsk/A are able to shed the extracellular domain of PAPC from the cell surface as efficiently as wild-type ADAM13, whereas the protease active-site mutant ADAM13-E/A cannot (Cousin et al., 2011; Figure 5A). Similarly, the phosphodeficient variants are also able to undergo autoproteolysis to shed their own ectodomain into the medium (Gaultier et al., 2002; Figure 5A). In addition, coexpressing Plk-DN or GSK3-DN does not prevent wild-type ADAM13 from shedding PAPC (unpublished data).
Affiliation: Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA 01003.