Thymocyte selection-associated protein (THEMIS)

Thymocyte selection-associated protein (THEMIS) is a highly conserved, T cell–specific signaling adaptor predominantly expressed during thymocyte development, particularly between the pre–T cell receptor (TCR) and the positive selection stages[1][2][4]. THEMIS plays an essential role in both positive and negative selection of thymocytes by integrating and sustaining TCR signals critical for CD4/CD8 lineage commitment and maturation[1][2][4][5]. Mechanistically, THEMIS modulates TCR signaling through its interaction with the adaptor protein GRB2 and the recruitment/inhibition of the tyrosine phosphatases SHP1 and SHP2, thereby fine-tuning kinase–phosphatase balance to set TCR signal thresholds required for effective selection outcomes[4][6][7]. THEMIS deficiency in mice results in impaired thymocyte selection, reduced numbers of single-positive T cells, and increased regulatory/memory T cell phenotypes, highlighting its pivotal role in T cell fate determination and immune system function[1][2][5].

Other names

Protein THEMISC6orf190C6orf207bA325O24.4FLJ40584bA325O24.3THEMIS1Thymocyte-expressed molecule involved in selectionGASPSPOTTSEPAGRB2-associated proteinsignaling phosphoprotein specific for T cellsthymocyte selection pathway associated