Involved in the unfolded protein response (UPR) during ER stress. Co-chaperone of HSPA8/HSC70, it stimulates its ATPase activity. May inhibit both the autophosphorylation of EIF2AK2/PKR and the ability of EIF2AK2 to catalyze phosphorylation of the EIF2A. May inhibit EIF2AK3/PERK activity. Interacts with EIF2AK3 and EIF2AK2. Forms a trimeric complex with DNAJB1 and HSPA8. Interacts with PRKRIR/P52RIPK. Up-regulated during an endoplasmic reticulum stress via ATF6. Activated in response to infection by influenza virus through the dissociation of DNAJB1. Down-regulated by DNAJB1 and PRKRIR/P52RIPK. Widely expressed with high level in the pancreas and testis. Also expressed in cell lines with different levels. Note: This description may include information from UniProtKB.
Protein type: Inhibitor protein; Endoplasmic reticulum; Protein kinase, regulatory subunit; Chaperone
Molecular Function: protein kinase inhibitor activity
Biological Process: cellular protein metabolic process; unfolded protein response, activation of signaling protein activity; unfolded protein response; negative regulation of protein kinase activity; defense response to virus
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.