GRP94: An HSP90-like protein specialized for protein folding and quality control in the endoplasmic reticulum

► GRP94 is an endoplasmic reticulum resident chaperone that belongs to HSP90 family. ► GRP94 chaperones secreted and membrane proteins. ► GRP94 is essential in development and physiology of multi-cellular organisms. ► GRP94 shares biochemical features with HSP90 but displays distinct activities.