Secretion of sup 35 SO sub 4 -labeled proteins from isolated rat hepatocytes

Journal Article · Tue May 02 04:00:00 EDT 1989 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00435a069· OSTI ID:5479030

von Wuertemberg, M M.F.; Fries, E ^[1]

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1. Univ. of Uppsala (Sweden)

Sulfation is a Golgi-specific modification of secretory proteins. We have characterized the proteins that are labeled with {sup 35}SO{sub 4} in cultures of rat hepatocytes and studied their transport to the medium. Analysis by polyacrylamide gel electrophoresis showed that of the five most heavily labeled proteins, four had well-defined mobilities--apparent molecular masses of 188, 142, 125, and 82 kDa--whereas one was electrophoretically heterogeneous--apparent molecular mass of 35-45 kDa. Judging by their relatively high resistance to acid treatment, the sulfate residues in the 125- and 35-45-kDa proteins were linked to carbohydrate. Some of the secreted proteins were sialylated. In samples of pulse-labeled cells, there appeared to be no unsialylated forms, indicating that sulfation occurred after sialylation, presumably in the trans Golgi. Kinetic experiments showed that the cellular half-life was the same for all the sulfated proteins--about 8 min--consistent with the idea that transport from the Golgi complex to the cell surface occurs by liquid bulk flow.

• OSTI ID: 5479030
• Journal Information: Biochemistry; (USA), Journal Name: Biochemistry; (USA) Vol. 28:9; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL HALF-LIFE
CELL CULTURES
DAYS LIVING RADIOISOTOPES
ELECTROPHORESIS
EVEN-ODD NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
LIVER CELLS
MAMMALS
MOLECULAR WEIGHT
NUCLEI
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PROTEINS
RADIOISOTOPES
RATS
RODENTS
SECRETION
SOMATIC CELLS
SULFATES
SULFUR 35
SULFUR COMPOUNDS
SULFUR ISOTOPES
TRACER TECHNIQUES
VERTEBRATES