Presence of the long and the short forms of Bcl-X in several human and murine tissues.
Bcl-X protein, which is related to Bcl-2, is present essentially in the nervous system and the immune system, under 2 different forms: Bcl-XL, like Bcl-2, is able to prevent apoptotic death of cultured lymphocytes; in contrast, Bcl-XS, which differs from the former one by a deletion of 63 amino acids in the region of greatest homology between Bcl-XL and Bcl-2, is unable to prevent this apoptotic death and even counteracts the protective effect of Bcl-2. It has been reported that the adult nervous system contains exclusively the RNA encoding Bcl-XL whereas the immune system would contain exclusively the RNA encoding Bcl- XS. We show here, by using reverse transcription coupled to PCR, that adult rat brain contains not only the RNA encoding Bcl-XL but also the RNA encoding Bcl- XS. Similarly we show that human lymphocytes, whether infected or not by the HIV, contain both forms of Bcl-X messenger RNA (mRNA). Furthermore we have observed that both forms of mRNA are present in adult rat liver and in cultured mouse hepatocytes. All these results have been confirmed by hybridizing the PCR products transferred to a nylon membrane with a probe specific of Bcl-XL or a non discriminative probe.
- PubMed
- Europe PMC
- C R Acad Sci III 318:537-540 ()