Proteasomes are Regulated by Interferon γ: Implications for Antigen Processing

• Published in: Proceedings of the National Academy of Sciences - PNAS 1992-06, Vol.89 (11), p.4928-4932
• Main Authors: Yang, Young, Waters, James B., Fruh, Klaus, Peterson, Per A.
• Format: Article
• Language: English
• Subjects: Analysis of the immune response. Humoral and cellular immunity; Animals; Antigen presentation; Antigens - metabolism; Biological and medical sciences; Cell Compartmentation; Cell lines; Chemical composition; Cysteine Endopeptidases - chemistry; Cysteine Endopeptidases - metabolism; Electrophoresis, Gel, Two-Dimensional; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Gels; HeLa Cells; Humans; Immunobiology; Interferon-gamma - physiology; Isoelectric Point; Lymphokines, interleukins ( function, expression); Macromolecular Substances; Major Histocompatibility Complex; Mice; Molecular Weight; Molecules; Multienzyme Complexes - chemistry; Multienzyme Complexes - metabolism; Physiological regulation; Proteasome Endopeptidase Complex; Quaternary ammonium compounds; Regulatory factors and their cellular receptors; Sulfates; T lymphocytes
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.89.11.4928

Class I major histocompatibility complex (MHC) molecules present antigenic peptides of cytoplasmic origin to T cells. As the lengths of these peptides seem restricted to eight or nine amino acids, an unusual proteolytic system must play a role in antigen processing. Proteasomes, a major extralysosomal proteolytic system, are responsible for the degradation of cytoplasmic proteins. We demonstrate that several proteasomal subunits, including MHC-encoded subunits, are regulated by interferon γ. These data and the finding that MHC-encoded and other interferon γ-regulated proteasomal subunits are uniquely associated with proteasomes strongly suggest that the immune system has recruited proteasomes for antigen processing.