Two putative subunits of a peptide pump encoded in the human major histocompatability complex class 2 region

Journal Article · Fri Nov 15 00:00:00 EST 1991 · Proceedings of the National Academy of Sciences of the United States of America; (United States)

DOI:https://doi.org/10.1073/pnas.88.22.10094· OSTI ID:5702113

Bahram, S; Arnold, D; Bresnahan, M; Strominger, J L; Spies, T ^[1]

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1. Harvard Medical School, Boston, MA (United States)

The class 2 region of the human major histocompatibility complex (MHC) may encode several genes controlling the processing of endogenous antigen and the presentation of peptide epitopes by MHC class 1 molecules to cytotoxic T lymphocytes. A previously described peptide supply factor (PSF1) is a member of the multidrug-resistance family of transporters and may pump cytosolic peptides into the membrane-bound compartment where class 1 molecules assemble. A second transporter gene, PSF2, was identified 10 kilobases (kb) from PSF1, near the class 2 DOB gene. The complete sequences of PSF1 and PSF2 were determined from cDNA clones. The translation products are closely related in sequence and predicted secondary structure. Both contain a highly conserved ATP-binding fold and share 25% homology in a hydrophobic domain with a tentative number of eight membrane-spanning segments. Based on the principle dimeric organization of these two domains in other transporters, PSF1 and PSF2 may function as complementary subunits, independently as homodimers, or both. Taken together with previous genetic evidence, the coregulation of PSF1 and PSF2 by {gamma} interferon and the to-some-degree coordinate transcription of these genes suggest a common role in peptide-loading of class 1 molecules, although a distinct function of PSF2 cannot be ruled out.

• OSTI ID: 5702113
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (United States), Vol. 88:22; ISSN 0027-8424
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
HISTOCOMPATIBILITY COMPLEX
GENE REGULATION
RECOMBINANT DNA
DNA SEQUENCING
DNA HYBRIDIZATION
INTERFERON
LYMPHOCYTES
MEMBRANE PROTEINS
MEMBRANE TRANSPORT
PEPTIDES
ANIMAL CELLS
ANTIGENS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CONNECTIVE TISSUE CELLS
DNA
GROWTH FACTORS
HYBRIDIZATION
LEUKOCYTES
LYMPHOKINES
MATERIALS
MITOGENS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
PROTEINS
SOMATIC CELLS
STRUCTURAL CHEMICAL ANALYSIS
550201* - Biochemistry- Tracer Techniques