Secretion of sulfated and nonsulfated forms of parathyroid chromogranin A (secretory protein-I)

Journal Article · Sun Feb 25 04:00:00 EST 1990 · Journal of Biological Chemistry; (USA)

OSTI ID:6945156

Gorr, S U; Cohn, D V ^[1]

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1. Univ. of Louisville, KY (USA)

Chromogranin A (secretory protein-I) is an acidic, sulfated glycoprotein found in secretory granules of most endocrine cells but not in exocrine or epithelial cells. Parathyroid chromogranin A is sulfated on tyrosine residues, whereas adrenal chromogranin A appears to be sulfated mainly on oligosaccharide residues. Chromogranin B, on the other hand, is tyrosine-sulfated in the bovine adrenal whereas this protein is absent from the parathyroid. The role of this tissue- or species-specific sulfation of chromogranin is not known. Tyrosine sulfation is a common post-translational modification of proteins in the exocytotic pathway and has been suggested to play a role in the sorting or intracellular transport of secretory proteins. To test this, porcine parathyroid tissue slices were metabolically labeled with 35SO4 and (3H)Lys, and the tissue and incubation medium analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunoblotting, and immunoprecipitation with chromogranin A-specific antiserum or by radioimmunoassay for parathormone. Secretion of total and 3H-labeled chromogranin A was about 3- and 7-fold higher, respectively, at 0.5 mM than at 3.0 mM Ca2+, and secretion of 35SO4-labeled chromogranin A was 67-fold higher. This indicates that either sulfated chromogranin A is directed primarily to the Ca2+-regulated pathway or that sulfation occurs following sorting to this pathway. Sodium chlorate (1-10 mM) inhibited sulfation in a dose-dependent manner by up to 95% but it had no effect on the onset or rate of chromogranin A secretion. These data indicate that regulated secretion of parathyroid chromogranin A does not require sulfation of tyrosine residues.

• OSTI ID: 6945156
• Journal Information: Journal of Biological Chemistry; (USA), Journal Name: Journal of Biological Chemistry; (USA) Vol. 265:6; ISSN JBCHA; ISSN 0021-9258
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOASSAY
BIOCHEMISTRY
BIOLOGICAL PATHWAYS
BODY
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CHEMISTRY
CYTOPLASM
DAYS LIVING RADIOISOTOPES
DIAGNOSTIC TECHNIQUES
DOMESTIC ANIMALS
DOSE-RESPONSE RELATIONSHIPS
ELECTROPHORESIS
ENDOCRINE GLANDS
EVEN-ODD NUCLEI
GLANDS
GLYCOPROTEINS
HYDROGEN COMPOUNDS
IMMUNOASSAY
IMMUNOLOGY
IN VITRO
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
LYSINE
MAMMALS
MOLECULAR WEIGHT
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
OXYGEN COMPOUNDS
PARATHYROID GLANDS
PROTEINS
RADIOASSAY
RADIOIMMUNOASSAY
RADIOIMMUNODETECTION
RADIOIMMUNOLOGY
RADIOISOTOPES
SECRETION
SULFATES
SULFUR 35
SULFUR COMPOUNDS
SULFUR ISOTOPES
SWINE
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES