Phosphorylation of bovine interphotoreceptor retinoid-binding protein (IRBP)

Conference · Thu May 01 04:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:7246558

Wiggert, B; Lee, L; Chader, G J

IRBP is the major soluble (glycolipo) protein of the interphotoreceptor matrix (IPM) and a putative intercellular retinoid-transport vehicle. The authors have now examined phosphorylation of proteins in a crude bovine IPM wash using ..gamma..-/sup 32/P-ATP. SDS-polyacrylamide gel electrophoresis (PAGE) of IPM proteins showed several phosphorylated protein bands, one of them migrating in the same position as purified IRBP. When an aliquot of phosphorylated IPM proteins was incubated overnight with /sup 3/H-retinol and subjected to either size-exclusion or ion-exchange HPLC, a peak of /sup 32/P was observed in both cases which coincided with /sup 3/H-retinol binding and had a retention time identical to that of purified IRBP. When phosphorylated IPM was subjected to Con A Sepharose affinity chromatography and the 50mM methyl ..cap alpha..-D-mannoside eluate chromatographed on ion-exchange HPLC, the /sup 32/P-peak was not present although a substantial amount of non-phosphorylated IRBP was recovered as assessed by SDS-PAGE and Western blotting. However, when the Con A Sepharose beads were dissolved in SDS and subjected to SDS-PAGE and Western blotting, a band of phosphorylated IRBP was observed, indicating that the phosphorylated IRBP was more tightly bound to the Con A Sepharose. The authors conclude that a fraction of IRBP can be phosphorylated by a yet to be characterized protein kinase and that the binding characteristics of IRBP are markedly altered by phosphorylation.

• Research Organization: National Institute of Health, Bethesda, MD
• OSTI ID: 7246558
• Report Number(s): CONF-8606151-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:6
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
ATP
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CARBOHYDRATES
CARBOXYLIC ACID ESTERS
CATTLE
CHEMICAL REACTIONS
CHROMATOGRAPHY
DAYS LIVING RADIOISOTOPES
DOMESTIC ANIMALS
ELECTROPHORESIS
ENZYMES
ESTERS
GLUCOPROTEINS
ION EXCHANGE CHROMATOGRAPHY
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LABELLED COMPOUNDS
LIGHT NUCLEI
LIQUID COLUMN CHROMATOGRAPHY
MAMMALS
NUCLEI
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHORYLATION
PHOSPHOTRANSFERASES
PROTEINS
RADIOISOTOPES
REACTION KINETICS
RETINOIC ACID
RUMINANTS
SACCHARIDES
SEPARATION PROCESSES
TRACER TECHNIQUES
TRANSFERASES
TRITIUM COMPOUNDS
VERTEBRATES