Anti-SIL1 antibody

Supplementary info

This supplementary information is collated from multiple sources and compiled automatically.

Activity summary

The SIL1 protein known also as nucleotide exchange factor SIL1 or BAP plays a mechanical role as an endoplasmic reticulum (ER)-localized nucleotide exchange factor for BiP a heat shock protein. SIL1 has a molecular mass of approximately 53 kDa. The expression of SIL1 occurs mainly in tissues with high secretory demand such as the pancreas and liver. It exists prominently within the lumen of the ER where it stabilizes protein folding by facilitating nucleotide exchange on BiP.

Biological function summary

SIL1 operates as a critical component for ER homeostasis and proteostasis. It assists the chaperone function of BiP by promoting ADP/ATP exchange which is an essential step in the protein folding cycle. SIL1 forms part of a complex network of proteins within the ER that regulate protein biosynthesis folding and degradation. Its interactive network ensures efficient ER functioning affecting the maturation and stability of secretory and membrane proteins.

Pathways

SIL1 interacts within both the unfolded protein response (UPR) and ER-associated degradation (ERAD) pathways. In the UPR SIL1's role in BiP activity ensures proper folding of nascent polypeptides reducing ER stress. In ERAD SIL1's actions facilitate misfolded protein processing and clearance. SIL1 is closely related to other chaperones and co-chaperones like GRP78 with whom it collaboratively maintains ER function under stress conditions ensuring cellular homeostasis.

Associated diseases and disorders

SIL1 mutations associate with Marinesco-Sjögren syndrome a rare autosomal recessive disorder. The syndrome results from disrupted protein homeostasis in the ER leading to multisystem clinical symptoms such as muscle weakness and cataracts. SIL1 also connects to neurodegenerative diseases often characterized by ER stress and faulty proteostasis implicating proteins such as BiP whose impairment also results from SIL1 malfunctions. Understanding these connections is essential for identifying potential therapeutic targets for these disorders.