COMBINATORIAL INTERACTION OF HUMAN BCL-2 RELATED PROTEINS - MAPPING OF REGIONS IMPORTANT FOR BCL-2 BCL-X-S INTERACTION/

Human bcl-2 family of genes including bcl-2, bcl-x-l, bcl-x-s, and bar has been shown to be functionally involved in apoptosis. We applied a yeast two-hybrid system to demonstrate that bcl-2, bcl-x-l, bcl-x-s, and bar proteins can interact with each other directly. All bcl-2 fami ly members except bar were shown to be capable of homo-interactions. B y using deletion and point mutations, the interaction domains for bcl- 2 and bcl-x-s were elucidated The BH1 domain and the membrane anchorin g region at the C-terminal half of the bcl-2 protein are required for its interaction with bcl-x-s. On the other hand, the N-terminal region consisting of codons 24 to 78 of bcl-x-s interacts with bcl-2. (C) 19 95 Academic Press, Inc.