<b>Dominant negative form of alpha4 inhibits the BCR crosslinking-induced phosphorylation of Bcl-xL and apoptosis in an immature B cell line WEHI-23</b><b>1 </b>

We previously demonstrated that c-Jun N-terminal kinase (JNK) phosphorylates serine 62 of Bcl-xL to induce the degradation of Bcl-xL and apoptosis in WEHI-231 cells upon BCR crosslinking. In order to elucidate the regulatory mechanisms underlying the phosphorylation of Bcl-xL, we prepared an assay system in which JNK phosphorylated Bcl-xL in HEK293T cells. Consequently, we found that a signal transduction molecule, alpha4, enhanced the...