Abstract
The endoplasmic reticulum stress response, also known as the unfolded protein response (UPR), has been implicated in the normal physiology of immune defense and in several disorders, including diabetes, cancer, and neurodegenerative disease. Here, we show that the apoptotic receptor CED-1 and a network of PQN/ABU proteins involved in a noncanonical UPR response are required for proper defense to pathogen infection in
Caenorhabditis elegans. A full-genome microarray analysis indicates that CED-1 functions to activate the expression of
pqn/abu genes. We also show that
ced-1 and
pqn/abu genes are required for the survival of
C.
elegans exposed to live
Salmonella enterica, and that overexpression of
pqn/abu genes confers protection against pathogen-mediated killing. The results indicate that unfolded protein response genes, regulated in a CED-1-dependent manner, are involved in the
C.
elegans immune response to live bacteria.
