A heat shock transcription factor like protein in the nuclear matrix compartment of the tissue cultured mammalian lens epithelial cell

This investigation characterizes a prominent nuclear matrix protein isolate d from tissue cultured mouse lens epithelia[ cells. The nuclear matrix prot ein was isolated using a modified Penman technique. Total nuclear matrix pr oteins were further separated by SDS-polyacrylamide gel electrophoresis. Th e SDS-PAGE profile of the nuclear matrix proteins displayed a prominent dou blet band at 60 kDa region. Nonequilibrium 2D gel electrophoresis revealed that this protein is a basic nuclear protein. This 60 kDa protein was furth er characterized by comparing its internal peptide amino acid sequence with known protein sequence using the BLAST technique, and this study demonstra ted that 60 kDa nuclear matrix protein displays significant sequence simila rity with Xenopus Laevis heat shock transcription factor. We also raised an tibodies against 60 kDa nuclear matrix protein. immunofluorescence, studies showed that this 60 kDa nuclear matrix protein preferably decorates nucleu s, and puncted pattern of fluorescence suggest presence of this protein in the discrete areas of the nucleus. Heat shock transcription factors upregul ate synthesis of heat shock proteins and many of these protein act as molec ular chaperones. Thus, presence of a nuclear matrix protein with significan t sequence similarity with heat shock transcription factor suggests sustain ed heat shock protein synthesis in the mouse lens cells. (C) 2001 Wiley-Lis s, Inc.