Activation/division of lymphocytes results in increased levels of cytoplasmic activation/proliferation-associated protein-1: prototype of a new family of proteins.

Details

Serval ID
serval:BIB_D69FD193B003
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Activation/division of lymphocytes results in increased levels of cytoplasmic activation/proliferation-associated protein-1: prototype of a new family of proteins.
Journal
Journal of Immunology
Author(s)
Grill B., Wilson G.M., Zhang K.X., Wang B., Doyonnas R., Quadroni M., Schrader J.W.
ISSN
0022-1767
Publication state
Published
Issued date
2004
Peer-reviewed
Oui
Volume
172
Number
4
Pages
2389-2400
Language
english
Notes
Publication types: Journal Article
Abstract
We purified from activated T lymphocytes a novel, highly conserved, 116-kDa, intracellular protein that occurred at high levels in the large, dividing cells of the thymus, was up-regulated when resting T or B lymphocytes or hemopoietic progenitors were activated, and was down-regulated when a monocytic leukemia, M1, was induced to differentiate. Expression of the protein was highest in the thymus and spleen and lowest in tissues with a low proportion of dividing cells such as kidney or muscle, although expression was high in the brain. The protein was localized to the cytosol and was phosphorylated, which is consistent with a previous report that the Xenopus laevis ortholog was phosphorylated by a mitotically activated kinase (1 ). The cDNA was previously mischaracterized as encoding p137, a 137-kDa GPI-linked membrane protein (2 ). We propose that the authentic protein encoded by this cDNA be called cytoplasmic activation/proliferation-associated protein-1 (caprin-1), and show that it is the prototype of a novel family of proteins characterized by two novel protein domains, termed homology regions-1 and -2 (HR-1, HR-2). Although we have found evidence for caprins only in urochordates and vertebrates, two insect proteins exhibit well-conserved HR-1 domains. The HR-1 and HR-2 domains have no known function, although the HR-1 of caprin-1 appeared necessary for formation of multimeric complexes of caprin-1. Overexpression of a fusion protein of enhanced green fluorescent protein and caprin-1 induced a specific, dose-dependent suppression of the proliferation of NIH-3T3 cells, consistent with the notion that caprin-1 plays a role in cellular activation or proliferation.
Keywords
Amino Acid Sequence, Animals, B-Lymphocytes/cytology, B-Lymphocytes/immunology, Cell Cycle Proteins/biosynthesis, Cell Cycle Proteins/chemistry, Cell Differentiation/immunology, Cell Division/immunology, Cell Line, Cell Line, Tumor, Conserved Sequence, Cytoplasm/immunology, Cytoplasm/metabolism, Green Fluorescent Proteins, Growth Inhibitors/chemistry, Growth Substances/deficiency, Hematopoiesis, Humans, Insect Proteins/chemistry, Luminescent Proteins/genetics, Lymphocyte Activation, Lymphopoiesis, Mice, Mice, Inbred C57BL, Mice, Inbred CBA, Molecular Sequence Data, Molecular Weight, NIH 3T3 Cells, Organ Specificity/immunology, Phosphoproteins/biosynthesis, Phosphoproteins/chemistry, Protein Structure, Tertiary, Sequence Homology, Amino Acid, T-Lymphocytes/cytology, T-Lymphocytes/immunology, Up-Regulation/immunology, Xenopus Proteins/biosynthesis, Xenopus Proteins/chemistry
Pubmed
Web of science
Create date
24/01/2008 15:46
Last modification date
20/08/2019 15:56
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