Thymocyte Expressed Molecule Involved In Selection (THEMIS)

THEMIS encodes a protein that plays a regulatory role in both positive and negative T-cell selection during late thymocyte development. The protein functions through T-cell antigen receptor signaling, and is necessary for proper lineage commitment and maturation of T-cells. Alternative splicing results in multiple transcript variants.

The predicted 641-amino acid human protein shares 81% identity with mouse Themis. Both human and mouse THEMIS contain a putative bipartite nuclear localization signal and a highly conserved C-terminal proline-rich region predicted to form 3 overlapping SH3 domain recognition motifs. RNA blot analysis revealed that mouse Themis was expressed in thymus and, to a lesser extent, in spleen, but not in nonlymphoid tissues.