Functional characterization of a neonatal heart expressing-protein - analysis of the protein-interacting partners of TSPYL-2

Abstract

Our group has found a novel gene, Testis-Specific-Protein Y encoded, Like-2 (TSPYL-2), which is expressed in heart. It has been reported that transfection of TSPYL-2 results in growth arrest in HeLa cells, but the exact roles of TSPYL-2 in cell growth are still unclear. To gain insights into the functions of TSPYL-2, we investigate the protein interacting partners of TSPYL-2. In the candidate approach, we found that TSPYL-2 contains a SET/NAP domain which is present in a family of p300/CBP and/or cyclin B1 binding proteins represented by the NAPI and oncoprotein SET. It suggests that p300/CBP and cyclin B1 may interact with TSPYL-2. However, neither of the candidates can co-immunoprecipitated with TSPYL-2. Using the pull-down approach, the transcriptional factor Neuronal Stem Cell Leukemia-2 (NSCL-2), is identified to interact with the N-terminal proline-rich domain of TSPYL-2. Further experiments to confirm the protein interaction by co-immunoprecipitation and mammalian two-hybrid assay are underway. References 1. Chai Z et al., SET-related cell division autoantigen-1 (CDA1) arrests cell growth., J Biol Chem. 2001;276(36):33665-74. 2. Kellogg D et al., Members of the NAP/SET family of proteins interact specifically with B-type cyclins., J Cell Biol. 1995;130(3):661-73. 3. Shikama N et al., Functional interaction between nucleosome assembly proteins and p300/CREB-binding protein family coactivators., Mol Cell Biol. 2000; 20(23):8933-43. 4. Sun G et al., Isolation of differentially expressed genes in human heart tissues., Biochim Biophys Acta. 2002;1588(3):241-6. * This project is partially supported by Edward Sai-Kim Hotung Paediatric Education and Research Fund.