Upr Signaling Induces Jnk Pathway Activation in Drosophila Melanogaster

We report in this paper the requirement of xbp-1 gene for regulating unfolded protein response (UPR) target genes and induced JNK pathway. The UPR is essential for cell survival during endoplasmic reticulum (ER). Upon ER stress, Dxbp-1 transcript was submitted to an "unconventional" splicing that generated a processed Dxbp-1 s transcript encoding DXbp-1 protein isform. Over-expression of Dxbp-1 s increased expression of the pDI gene, a known UPR target, but high levels of Dxbp-1s also induced embryonic lethality associated with activate JNK pathway