In search of a function for the TIS21/PC3/BTG1/TOB family

The Btg family of anti-proliferative gene products includes Pc3/Tis21/Btg2, Btg1, Tob, Tob2, Ana/Btg3, Pc3k and others. These proteins are characteriz ed by similarities in their amino-terminal region: the Btg1 homology domain . However, the pleiotropic nature of these family proteins has been observe d and no common physiological function among family members was suggested f rom the history of their identification. Recent progress in the search for Btg family functions has come from the analysis of cell regulation and of c ell differentiation. It is now emerging that every member of this family ha s a potential to regulate cell growth. We would like to propose here to use a nomenclature APRO as a new term for the family. (C) 2001 Federation of E uropean Biochemical Societies. Published by Elsevier Science B,V, All right s reserved.