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J Cell Biol
1995 Jun 01;1296:1641-50. doi: 10.1083/jcb.129.6.1641.
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7B2 facilitates the maturation of proPC2 in neuroendocrine cells and is required for the expression of enzymatic activity.
Zhu X
,
Lindberg I
.
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The prohormone convertase PC2, which is thought to mediate the proteolytic conversion of many peptide hormones, has recently been shown to interact with the neuroendocrine-specific polypeptide 7B2 in Xenopus intermediate lobe (Braks, J. A. M., and G. J. M. Martens. Cell. 78:263. 1994). In the present work we have stably transfected neuroendocrine cell lines with rat 7B2 constructs and found that overexpression of 27 kD 7B2 greatly facilitates the kinetics of maturation of proPC2, both in AtT-20/PC2 cells and in Rin5f cells. The half-life of conversion of proPC2 was reduced from 2.7 to 1.7 h in AtT-20/PC2 cells stably transfected with 27 kD 7B2 cDNA. The previously proposed "chaperone" domain was not sufficient for this facilitation event; however, a construct corresponding to the 21-kD 7B2 protein (which represents the naturally occurring maturation product) functioned well. A 7B2 construct in which maturation of 27 kD 7B2 to its 21-kD form was blocked was unable to facilitate maturation of proPC2. To correlate effects on PC2 maturation with the actual generation of PC2 enzymatic activity, a similar transfection of 21 kD 7B2 was performed using CHO cells previously amplified for the expression of proPC2. Enzymatic activity cleaving the fluorogenic substrate Cbz-Arg-Ser-Lys-Arg-AMC was highly correlated with the expression of immunoreactive 21 kD 7B2 in the conditioned medium; medium obtained from the parent cell line was completely inactive. Enzymatic activity was identified as PC2 on the basis of inhibition by the carboxy-terminal peptide of 7B2, which has previously been shown to represent a potent and specific PC2 inhibitor. Taken together, our in vivo results indicate that the interesting secretory protein 7B2 is a bifunctional molecule with an amino-terminal domain involved in proPC2 transport as well as activation.
Ayoubi,
The neuroendocrine polypeptide 7B2 is a precursor protein.
1990, Pubmed,
Xenbase
Ayoubi,
The neuroendocrine polypeptide 7B2 is a precursor protein.
1990,
Pubmed
,
Xenbase
Benjannet,
PC1 and PC2 are proprotein convertases capable of cleaving proopiomelanocortin at distinct pairs of basic residues.
1991,
Pubmed
Benjannet,
7B2 is a specific intracellular binding protein of the prohormone convertase PC2.
1995,
Pubmed
Benjannet,
Comparative biosynthesis, covalent post-translational modifications and efficiency of prosegment cleavage of the prohormone convertases PC1 and PC2: glycosylation, sulphation and identification of the intracellular site of prosegment cleavage of PC1 and PC2.
1993,
Pubmed
Braks,
7B2 is a neuroendocrine chaperone that transiently interacts with prohormone convertase PC2 in the secretory pathway.
1994,
Pubmed
,
Xenbase
Breslin,
Differential processing of proenkephalin by prohormone convertases 1(3) and 2 and furin.
1993,
Pubmed
Goodman,
Autoproteolytic activation of the mouse prohormone convertase mPC1.
1994,
Pubmed
Guest,
The post-translational processing and intracellular sorting of PC2 in the islets of Langerhans.
1992,
Pubmed
Hsi,
Isolation and NH2-terminal sequence of a novel porcine anterior pituitary polypeptide. Homology to proinsulin, secretin and Rous sarcoma virus transforming protein TVFV60.
1982,
Pubmed
Hutton,
Subtilisin-like proteinases involved in the activation of proproteins of the eukaryotic secretory pathway.
1990,
Pubmed
Iguchi,
Tissue distribution and molecular forms of a novel pituitary protein in the rat.
1984,
Pubmed
Lindberg,
Cellular distributions of the prohormone processing enzymes PC1 and PC2.
1994,
Pubmed
Lindberg,
Enzymatic characterization of immunopurified prohormone convertase 2: potent inhibition by a 7B2 peptide fragment.
1995,
Pubmed
Lindberg,
Fluorometric assay of a calcium-dependent, paired-basic processing endopeptidase present in insulinoma granules.
1992,
Pubmed
Lindberg,
Evidence for cleavage of the PC1/PC3 pro-segment in the endoplasmic reticulum.
1994,
Pubmed
Martens,
The neuroendocrine polypeptide 7B2 is an endogenous inhibitor of prohormone convertase PC2.
1994,
Pubmed
Mathis,
Posttranslational processing of proenkephalin in AtT-20 cells: evidence for cleavage at a Lys-Lys site.
1992,
Pubmed
Matthews,
Autocatalytic maturation of the prohormone convertase PC2.
1994,
Pubmed
,
Xenbase
Milgram,
Differential effects of temperature blockade on the proteolytic processing of three secretory granule-associated proteins.
1994,
Pubmed
Paquet,
The neuroendocrine precursor 7B2 is a sulfated protein proteolytically processed by a ubiquitous furin-like convertase.
1994,
Pubmed
Paquet,
Immunological identification and sequence characterization of a peptide derived from the processing of neuroendocrine protein 7B2.
1991,
Pubmed
Seidah,
Isolation and NH2-terminal sequence of a highly conserved human and porcine pituitary protein belonging to a new superfamily. Immunocytochemical localization in pars distalis and pars nervosa of the pituitary and in the supraoptic nucleus of the hypothalamus.
1983,
Pubmed
Shen,
Biosynthesis of the prohormone convertase PC2 in Chinese hamster ovary cells and in rat insulinoma cells.
1993,
Pubmed
Shennan,
Differences in pH optima and calcium requirements for maturation of the prohormone convertases PC2 and PC3 indicates different intracellular locations for these events.
1995,
Pubmed
,
Xenbase
Sigafoos,
Identification of a 7B2-derived tridecapeptide from bovine adrenal medulla chromaffin vesicles.
1993,
Pubmed
,
Xenbase
Steiner,
The new enzymology of precursor processing endoproteases.
1992,
Pubmed
Thomas,
Kex2-like endoproteases PC2 and PC3 accurately cleave a model prohormone in mammalian cells: evidence for a common core of neuroendocrine processing enzymes.
1991,
Pubmed
Vallette,
Construction of mutant and chimeric genes using the polymerase chain reaction.
1989,
Pubmed
Waldbieser,
Cloning and characterization of the rat complementary deoxyribonucleic acid and gene encoding the neuroendocrine peptide 7B2.
1991,
Pubmed
Zhou,
Purification and characterization of the prohormone convertase PC1(PC3).
1993,
Pubmed
Zhou,
The prohormone convertases PC1 and PC2 mediate distinct endoproteolytic cleavages in a strict temporal order during proopiomelanocortin biosynthetic processing.
1993,
Pubmed
Zhou,
Enzymatic properties of carboxyl-terminally truncated prohormone convertase 1 (PC1/SPC3) and evidence for autocatalytic conversion.
1994,
Pubmed
Zhou,
Endoproteolytic processing of proopiomelanocortin and prohormone convertases 1 and 2 in neuroendocrine cells overexpressing prohormone convertases 1 or 2.
1994,
Pubmed
