LEDGF activation of PKC γ and gap junction disassembly in lens epithelial cells

详细信息    查看全文

• 作者：Nguyen ; Thu Annelise ; Boyle ; Daniel L. ; Wagner ; Lynn M. ; Shinohara ; Toshimichi ; Takemoto ; Dolores J.
• 关键词：LEDGF ; PKC γ ; Connexin 43 ; gap junction communication ; lens epithelial cells
• 刊名：Experimental Eye Research
• 出版年：2003
• 出版时间：May, 2003
• 年：2003
• 卷：76
• 期：5
• 页码：565-572
• 全文大小：383 K

文摘

Lens epithelium-derived growth factor (LEDGF) has been shown to enhance survival of lens epithelial cells (LECs) against stress. The objectives of these studies are to determine how LEDGF controls PKC γ activity in normal LECs: how this control of PKC γ regulates the phosphorylation of Connexin 43, the inhibition of gap junction activity, and the prevention of assembly of gap junctions in LECs. A rabbit LEC line, N/N1003A, was grown in the absence or presence of LEDGF. PKC γ protein was translocated from the cytosolic fractions to the membrane fractions upon addition of LEDGF at 10ngml⁻¹. In whole cell extracts of N/N1003A cells, co-immunoprecipitation assays showed a protein–protein interaction between PKC γ and Connexin 43. In the presence of LEDGF the activation of PKC γ enhanced the phosphorylation of Connexin 43 by four-fold compared to the absence of LEDGF. The addition of LEDGF for 30min resulted in a 65 % decrease in gap junction Connexin 43 at the cell surface and a 70 % decrease in gap junction activity. These results suggest that the activation of PKC γ by LEDGF plays a major role in gap junction assembly/disassembly, which may enhance survival of LECs against osmolarity-stress induced by high sugar concentration.