Nonchromatin nuclear proteins of mammalian lens epithelial cells

The nuclear matrix (NM) proteins of six tissue cultured lens epithelial cell lines and one embryonic rabbit epidermal cell line were analyzed to determined possible tissue and species specificity of these proteins. The NM proteins were isolated by the modified Penman technique. The tissue cultured cells were pulsed with [35S] methionine and nuclear matrix proteins were fractionated by two-dimensional (2-D) gel electrophoresis. The 2-D gels were dried and autoradiographed. The relative abundance of spot patterns of nuclear matrix proteins of different cells were compared. The data from these experiments revealed that all the examined cell lines have distinct spot patterns, however, all of NM profile showed a spot pattern in the 45 kDa region with acidic pH. Some of these spots cross-reacted with anti-vimentin antibodies, whereas a prominent protein spot in this region did not cross react with either vimentin or actin antibodies. The observed variations in the NM protein patterns of lens epithelial cells may reflect tissue and species specificity and also a role in the regulatory properties of these nuclear proteins in the eye tissue development.