Differential association of rat liver heparan sulfate proteoglycans in membranes of the Golgi apparatus and the plasma membrane

Journal Article · Sun Jun 25 04:00:00 EDT 1989 · J. Biol. Chem.; (United States)

OSTI ID:5768380

Brandan, E; Hirschberg, C B

Heparan sulfate proteoglycans (HSPG) of rat liver are associated with the plasma membrane in a hydrophobic intrinsic and a hydrophilic extrinsic form. We were interested in determining whether or not these two forms could be detected in the Golgi apparatus, the subcellular site of addition of oligosaccharides and sulfate to HSPG. In vivo and in vitro radiolabeled HSPG from rat liver Golgi apparatus membranes could only be solubilized with detergents that disrupt the membrane lipid bilayer, suggesting that they are solely associated via hydrophobic interactions. Both forms of HSPG were detected in plasma membranes of rat liver and isolated rat hepatocytes. The detergent-solubilized HSPG bound to octyl-Sepharose columns, whereas the hydrophilic form did not; this latter form, however, was released from the membrane by heparin. The hydrophobic anchor of HSPG in the Golgi and plasma membranes was insensitive to treatment with phosphatidylinositol-specific phospholipase C under conditions in which alkaline phosphatase was sensitive; this suggests that the hydrophobic anchor of HSPG is the core protein itself. Preliminary experiments suggest that the subcellular site of processing of the hydrophobic to the hydrophilic form of HSPG is the plasma membrane. A specific processing activity, probably a protease of the plasma membrane not present in serum or the endoplasmic reticulum membrane, converted hydrophobic HSPG of the Golgi membrane to the hydrophilic form. In addition, pulse-chase experiments with (35S)Na2SO4 in rats demonstrated that at short times, the bulk of the radiolabeled cellular HSPG was in the Golgi apparatus; later on, the bulk of the radioactivity was found in the plasma membrane, the only subcellular site where the hydrophilic form of HSPG was detected.

• Research Organization: Catholic Univ. of Chile, Santiago
• OSTI ID: 5768380
• Journal Information: J. Biol. Chem.; (United States), Journal Name: J. Biol. Chem.; (United States) Vol. 264:18; ISSN JBCHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINES
ANIMALS
ANTICOAGULANTS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BODY
CARBOHYDRATES
CELL CONSTITUENTS
CELL MEMBRANES
CHONDROITIN
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
DISTRIBUTION
DRUGS
ENZYMES
EVEN-ODD NUCLEI
GLANDS
GLYCOPROTEINS
HEMATOLOGIC AGENTS
HEPARIN
HYDROLASES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LIGHT NUCLEI
LIVER
MAMMALS
MEMBRANES
MUCOPOLYSACCHARIDES
NUCLEI
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANOIDS
ORGANS
OXYGEN COMPOUNDS
PEPTIDE HYDROLASES
POLYSACCHARIDES
PROTEINS
RADIOISOTOPES
RATS
REACTION KINETICS
RODENTS
SACCHARIDES
SUBCELLULAR DISTRIBUTION
SULFATES
SULFUR 35
SULFUR COMPOUNDS
SULFUR ISOTOPES
TRACER TECHNIQUES
VERTEBRATES