Human cyclophilin B: A second cyclophilin gene encodes a peptidyl-prolyl isomerase with a signal sequence

Journal Article · Fri Mar 01 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.88.5.1903· OSTI ID:6045266

Price, E R; Zydowsky, L D; Jin, Mingjie; Baker, C H; McKeon, F D; Walsh, C T ^[1]

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

The authors report the cloning and characterization of a cDNA encoding a second human cyclosporin A-binding protein (hCyPB). Homology analyses reveal that hCyPB is a member of the cyclophilin B (CyPB) family, which includes yeast CyPB, Drosophila nina A, and rat cyclophilin-like protein. This family is distinguished from the cyclophilin A (CyPA) family by the presence of endoplasmic reticulum (ER)-directed signal sequences. hCyPB has a hydrophobic leader sequence not found in hCyPA, and its first 25 amino acids are removed upon expression in Escherichia coli. Moreover, they show that hCyPB is a peptidyl-prolyl cis-trans isomerase which can be inhibited by cyclosporin A. These observations suggest that other members of the CyPB family will have similar enzymatic properties. Sequence comparisons of the CyPB proteins show a central, 165-amino acid peptidyl-prolyl isomerase and cyclosprorin A-binding domain, flanked by variable N-terminal and C-terminal domains. These two variable regions may impart compartmental specificity and regulation to this family of cyclophilin proteins containing the conserved core domain. Northern blot analyses show that hCyPB mRNA is expressed in the Jurkat T-cell line, consistent with its possible target role in cyclosporin A-mediated immunosuppression.

• OSTI ID: 6045266
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (United States), Vol. 88:5; ISSN 0027-8424
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
IMMUNOSUPPRESSIVE DRUGS
BIOCHEMISTRY
ISOMERASES
AMINO ACID SEQUENCE
RECOMBINANT DNA
DNA SEQUENCING
ESCHERICHIA COLI
HELA CELLS
IMMUNOSUPPRESSION
MESSENGER-RNA
PHOSPHORUS 32
PROLINE
AMINES
AMINO ACIDS
AZOLES
BACTERIA
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBOXYLIC ACIDS
CHEMISTRY
DAYS LIVING RADIOISOTOPES
DNA
DRUGS
ENZYMES
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
ISOTOPES
LIGHT NUCLEI
MICROORGANISMS
MOLECULAR STRUCTURE
NUCLEI
NUCLEIC ACIDS
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOSPHORUS ISOTOPES
PYRROLES
PYRROLIDINES
RADIOISOTOPES
RNA
STRUCTURAL CHEMICAL ANALYSIS
550201* - Biochemistry- Tracer Techniques