Abstract
Abstract: :
Purpose: Cadherins are typically referred to as cell adhesion molecules, however a number of cadherin types within the cadherin superfamily are not involved in adhesion per se. Two atypical cadherins that we have identified in two different rat retinal cDNA libraries are T-cadherin and MT-protocadherin. The exact function of either cadherin is not clear. T-cadherin may be involved in a signal transduction pathway that mediates a cellular sensor. MT-protocadherin, as with other protocadherins, is implicated in central nervous system function. Little is known of the function of these genes in the retina. Our current purpose is to examine the expression of these two genes in relation to retinal function and retinal degeneration. Methods and Results: Differential cross-screens were performed on two rat retinal cDNA libraries, an 8h light exposed retina cDNA library and a brimonidine treated retinal cDNA library. Sequence analysis was performed on the isolated clones and BLAST database searches were carried out to determine putative identities of these clones. Two clones of interest, T-cadherin (from the light exposed library) and MT-protocadherin (from the brimonidine treated library) were isolated. Our primary interest was to examine the expression of these genes in the face of retinal degeneration. Analysis of these clones involved confirmation of their differential status and determination of their tissue expression by northern analysis. As well, in silico analysis was performed to determine the gene structure of T-cadherin and MT-protocadherin. Conclusion: Analysis and characterization of these two atypical cadherins indicates that changes in their expression are involved in retinal degeneration; however, the exact role they play has not been elucidated. To our knowledge, this is the first report of the isolation and identification of the rat T-cadherin homologue. Further analysis of these cadherins will involve the determination of the protein and RNA localization in retinal tissue via immunohistochemistry and in situ analysis, respectively. Support: FFS (RK); NSERC (PW; RG; MC); FFB Canada (MP); NIH Grant EY-01959 (DTO).
Keywords: 561 retinal degenerations: cell biology • 339 cell adhesions/cell junctions • 341 cell death/apoptosis