TULA-family proteins: an odd couple.
Two members of the TULA family (TULA/STS-2/UBASH3A and TULA-2/STS-1/UBASH3B) recently emerged as novel regulators of several cellular functions. The degree of structural similarity between the TULA-family proteins is typical for proteins that belong to the same family. Furthermore, the experiments with knockout mice lacking these proteins may be interpreted as suggesting that functions of TULA-family proteins in T lymphocytes overlap. At the same time, TULA and TULA-2 exhibit clear functional dissimilarities, starting with the finding that a conserved phosphatase domain present in both proteins exhibits remarkable differences in enzymatic activity; TULA-2 is an active phosphatase capable of dephosphorylating multiple tyrosine-phosphorylated proteins, whereas the phosphatase activity of TULA is extremely low. In contrast, TULA, but not TULA-2, facilitates growth factor withdrawal-induced apoptosis in T cells. In spite of their apparent importance, the functional role of TULA-family proteins is not well understood. In particular, the role of functional dissimilarities between them remains unclear.
Tsygankov
Alexander Y
AY
Department of Microbiology and Immunology, Sol Sherry Thrombosis Center and Fels Institute for Cancer Research and Molecular Biology, Temple University School of Medicine, Philadelphia, PA 19140, USA. alexander.tsygankov@temple.edu
D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013601:T-Lymphocytes / Q000502:physiology
C489394:CLIP4 protein, human; D002352:Carrier Proteins; D008565:Membrane Proteins; D020033:Protein Isoforms