Recombinant Human GILT protein

Supplementary information

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

Gamma-interferon-inducible lysosomal thiol reductase often called GILT is a thiol reductase enzyme with a mass of about 35 kDa. GILT is expressed predominantly in antigen-presenting cells where it resides in the lysosomes. Mechanically GILT catalyzes the reduction of disulfide bonds in proteins which enables proteins to unfold under mild acidic conditions found in lysosomal compartments. GILT activity requires the catalytic cysteine residue which is essential for its function as a reductase.

Biological function summary

GILT contributes to the processing and presentation of antigens. By reducing disulfide bonds in endocytosed proteins GILT prepares them for subsequent degradation by lysosomal proteases. This function means it plays a significant role in the immune response as it aids the generation of peptides presented on major histocompatibility complex (MHC) class II molecules. GILT is not known to be part of a larger protein complex but interacts with other components within the lysosome to accomplish its task.

Pathways

GILT is integral to the antigen processing and presentation pathway mediated by MHC class II molecules. This pathway is critical for the initiation of immune responses and involves collaboration with other proteins such as cathepsins. The reduction of disulfide bonds by GILT allows cathepsins to efficiently degrade proteins into peptide fragments. These peptides then bind to MHC class II molecules which are presented on the cell surface for recognition by CD4+ T cells.

Altered GILT function has been linked to autoimmune diseases and cancer. In certain autoimmune disorders dysregulation of GILT can lead to improper antigen presentation contributing to the body's immune response against its own tissues. In cancer some tumors may downregulate GILT to escape immune surveillance by reducing antigen presentation. Interactions between GILT and other proteins such as MHC class II facilitate these pathological processes highlighting the importance of GILT in maintaining immune system balance.