Pun Renju, Cavanaugh Ann M, Aldrich Emily, Tran Olivia, Rudd Justin C, Hansen Laura A, North Brian J
Biomedical Sciences Department, School of Medicine, Creighton University, Omaha, NE 68178, USA.
Department of Biology, College of Arts and Sciences, Creighton University, Omaha, NE 68178, USA.
iScience. 2024 Jan 29;27(3):109033. doi: 10.1016/j.isci.2024.109033. eCollection 2024 Mar 15.
Downregulation of intercellular communication through suppression of gap junctional conductance is necessary during wound healing. Connexin 43 (Cx43), a prominent gap junction protein in skin, is downregulated following wounding to restrict communication between keratinocytes. Previous studies found that PKCμ, a novel PKC isozyme, regulates efficient cutaneous wound healing. However, the molecular mechanism by which PKCμ regulates wound healing remains unknown. We have identified that PKCμ suppresses intercellular communication and enhances cell migration in an wound healing model by regulating Cx43 containing gap junctions. PKCμ can directly interact with and phosphorylate Cx43 at S368, which leads to Cx43 internalization and downregulation. Finally, utilizing phosphomimetic and non-phosphorylatable S368 substitutions and gap junction inhibitors, we confirmed that PKCμ regulates intercellular communication and wound healing by controlling Cx43-S368 phosphorylation. These results define PKCμ as a critical regulator of Cx43 phosphorylation to control cell migration and wound healing in keratinocytes.
在伤口愈合过程中，通过抑制间隙连接电导来下调细胞间通讯是必要的。连接蛋白43（Cx43）是皮肤中一种重要的间隙连接蛋白，受伤后会下调，以限制角质形成细胞之间的通讯。先前的研究发现，新型蛋白激酶C亚型PKCμ可调节皮肤伤口的有效愈合。然而，PKCμ调节伤口愈合的分子机制仍不清楚。我们已经确定，在伤口愈合模型中，PKCμ通过调节含有Cx43的间隙连接来抑制细胞间通讯并增强细胞迁移。PKCμ可以直接与Cx43相互作用，并使其在S368位点磷酸化，从而导致Cx43内化和下调。最后，利用模拟磷酸化和不可磷酸化的S368替代物以及间隙连接抑制剂，我们证实PKCμ通过控制Cx43-S368磷酸化来调节细胞间通讯和伤口愈合。这些结果确定PKCμ是Cx43磷酸化的关键调节因子，可控制角质形成细胞的细胞迁移和伤口愈合。
