aPKC phosphorylates JAM-A at Ser285 to promote cell contact maturation and tight junction formation

作者：Iden Sandra; Misselwitz Steve; Peddibhotla Swetha S D; Tuncay Huseyin; Rehder Daniela; Gerke Volker; Robenek Horst; Suzuki Atsushi; Ebnet Klaus^*

来源：The Journal of Cell Biology, 2012, 196(5): 623-639.

DOI：10.1083/jcb.201104143

The PAR-3-atypical protein kinase C (aPKC)-PAR-6 complex has been implicated in the development of apicobasal polarity and the formation of tight junctions (TJs) in vertebrate epithelial cells. It is recruited by junctional adhesion molecule A (JAM-A) to primordial junctions where aPKC is activated by Rho family small guanosine triphosphatases. In this paper, we show that aPKC can interact directly with JAM-A in a PAR-3-independent manner. Upon recruitment to primordial junctions, aPKC phosphorylates JAM-A at S285 to promote the maturation of immature cell-cell contacts. In fully polarized cells, S285-phosphorylated JAM-A is localized exclusively at the TJs, and S285 phosphorylation of JAM-A is required for the development of a functional epithelial barrier. Protein phosphatase 2A dephosphorylates JAM-A at S285, suggesting that it antagonizes the activity of aPKC. Expression of nonphosphorylatable JAM-A/S285A interferes with single lumen specification during cyst development in three-dimensional culture. Our data suggest that aPKC phosphorylates JAM-A at S285 to regulate cell-cell contact maturation, TJ formation, and single lumen specification.

• 出版日期2012-3-5
• 单位河北医科大学