Role of N-linked oligosaccharides in the transport activity of the Na+/H+ antiporter in rat renal brush-border membrane

Journal Article · Sun Sep 25 04:00:00 EDT 1988 · J. Biol. Chem.; (United States)

OSTI ID:6703436

Yusufi, A N; Szczepanska-Konkel, M; Dousa, T P

The role of N-linked oligosaccharide side chains in the biogenesis and function of Na+-coupled transporters in renal luminal brush-border membrane (BBM) is not known. We examined the question of how in vivo inhibition by alkaloid swainsonine of alpha-mannosidase, a key enzyme in processing of glycoproteins in the Golgi apparatus, affects Na+/H+ antiport and Na+/Pi symport as well as activities of other transporters and enzymes in rat renal BBM. Administration of swainsonine to thyroparathyroidectomized rats, control or treated with 3,5,3'-triiodothyronine, markedly decreased the rate of Na+/H+ antiport, but had no effect on the rate of Na+/Pi symport across renal BBM vesicles (BBMV). Moreover, administration of swainsonine did not change activities of Na+ gradient, ((extravesicular Na+) greater than (intravesicular Na+))-dependent transport of D-glucose, L-proline, or the amiloride-insensitive 22Na+ uptake by BBMV; the activities of the BBM enzymes alkaline phosphatase, gamma-glutamyltransferase, or leucine aminopeptidase in BBMV were also not changed. The in vitro enzymatic deglycosylation of BBM by incubating freshly isolated BBMV with bacterial endoglycosidase F also resulted in a decreased rate of Na+/H+ antiport, but not Na+-coupled symports of Pi, L-proline, and D-glucose, or the activities of the BBM enzymes were not significantly affected. Similar incubation with endoglycosidase H was without effect on any of these parameters. Both the modification of BBMV glycoproteins by administration fo swainsonine in vivo as well as the in vitro incubation of BBMV with endoglycosidase F resulted in a decrease of the apparent Vmax of Na+/H+ antiport, but did not change the apparent Km of this antiporter for extravesicular Na+ and did not increase H+ conductance of BBM.

• Research Organization: Mayo Clinic and Foundation, Rochester, MN (USA)
• OSTI ID: 6703436
• Journal Information: J. Biol. Chem.; (United States), Journal Name: J. Biol. Chem.; (United States) Vol. 263:27; ISSN JBCHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALI METAL COMPOUNDS
ALKALI METAL ISOTOPES
ALKALINE PHOSPHATASE
ALKALOIDS
AMINOPEPTIDASES
ANIMALS
AZOLES
BARYONS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BIOLOGICAL FUNCTIONS
BIOTIN
BODY
CARBOHYDRATES
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CELL MEMBRANES
ELEMENTARY PARTICLES
ENZYME INHIBITORS
ENZYMES
ESTERASES
FERMIONS
FUNCTIONS
HADRONS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HORMONES
HYDROLASES
IMIDAZOLES
ISOTOPE APPLICATIONS
ISOTOPES
KIDNEYS
LIGHT NUCLEI
MAMMALS
MEMBRANE TRANSPORT
MEMBRANES
NUCLEI
NUCLEONS
ODD-ODD NUCLEI
OLIGOSACCHARIDES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANS
OXYGEN COMPOUNDS
PEPTIDE HORMONES
PEPTIDE HYDROLASES
PHOSPHATASES
PHOSPHATES
PHOSPHORUS COMPOUNDS
PROTONS
RADIOISOTOPES
RATS
RODENTS
SACCHARIDES
SODIUM 22
SODIUM COMPOUNDS
SODIUM ISOTOPES
THYROID HORMONES
TRACER TECHNIQUES
TRANSFERASES
TRIIODOTHYRONINE
VERTEBRATES
VITAMIN B GROUP
VITAMINS
YEARS LIVING RADIOISOTOPES