Tuyển tập các báo cáo nghiên cứu khoa học ngành y học tạp chí Medical Sciences dành cho các bạn sinh viên ngành y tham khảo đề tài: PKC and PKA Phosphorylation Affect the Subcellular Localization of Claudin-1 in Melanoma Cells. | Int. J. Med. Sci. 2009 6 93 International Journal of Medical Sciences 2009 6 2 93-101 Ivyspring International Publisher. All rights reserved Research Paper PKC and PKA Phosphorylation Affect the Subcellular Localization of Claudin-1 in Melanoma Cells Amanda D. French1 Jennifer L. Fiori1 Tura C. Camilli1 Poloko D. Leotlela1 Michael P. O Connell1 Brittany P. Frank2 Sarah Subaran2 Fred. E. Indig2 Dennis D. Taub1 and Ashani T. Weeraratna1 M 1. Laboratory of Immunology National Institute on Aging Baltimore MD 21124 USA 2. Research Resources Branch National Institute on Aging Baltimore MD 21124 USA Present Address Laboratory of Clinical Investigation National Institute on Aging Baltimore MD 21124 USA H Correspondence to Ashani T. Weeraratna PhD Laboratory of Immunology National Institutes of Health National Institute on Aging Biomedical Research Center 251 Bayview Blvd RM 08C226 Baltimore Maryland 21224. Voice 410 558-8146 Fax 410 558-8284 Email weerarat@ Received Accepted Published Abstract Cytoplasmic expression of claudin-1 in metastatic melanoma cells correlates to increased migration and increased secretion of MMP-2 in a PKC dependent manner whereas claudin-1 nuclear expression is found in benign nevi. Melanoma cells were transfected with a vector expressing CLDN-1 fused to a nuclear localization signal NLS . Despite significant nuclear localization of claudin-1 there was still transport of claudin-1 to the cytoplasm. Phorbol ester treatment of cells transfected with NLS-claudin-1 resulted in an exclusion of claudin-1 from the nucleus despite the NLS. To ascertain whether PKC or PKA were involved in this translocation we mutated the putative phosphorylation sites within the protein. We found that mutating the PKC phosphorylation sites to mimic a non-phosphorylated state did not cause a shift of claudin-1 to the nucleus of the cells but mutating the PKA sites did. Mutations of either site to mimic constitutive .
