PAR3 and aPKC regulate Golgi organization through CLASP2 phosphorylation to generate cell polarity.
Bottom Line: CLASP2 is known to localize to the TGN through its interaction with the TGN protein GCC185.This interaction was inhibited by the aPKC-mediated phosphorylation of CLASP2.Furthermore, the nonphosphorylatable mutant enhanced the colocalization of CLASP2 with GCC185, thereby perturbing the Golgi organization.
Affiliation: Department of Cell Pharmacology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan.Show MeSH
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Mentions: To explore the mechanism regulating the localization of CLASP2 to the TGN dependent on PAR3 and aPKC, we examined the involvement of PAR3 and aPKC in the interaction between CLASP2 and GCC185. On the basis of a previous report (Lin et al., 2011), we used dithiobis succinimidyl propionate (DSP) as a cross-linker for the immunoprecipitation of endogenous CLASP2-GCC185 complex. Under the condition in which CLASP2 was coprecipitated with GCC185 from control cells, PAR3 depletion increased the amount of CLASP2 coprecipitated with GCC185 (Figure 5A), suggesting that PAR3 negatively regulates the interaction between CLASP2 and GCC185. The effects of aPKC depletion were inconclusive because the treatment of the cross-linker with aPKC-depleted cells drastically decreased the GCC185 solubility for the immunoprecipitation.
Affiliation: Department of Cell Pharmacology, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan.