Mechanism of phosphorylation in the lumen of the Golgi apparatus. Translocation of adenosine 5'-triphosphate into Golgi vesicles from rat liver and mammary gland

Journal Article · Sat Mar 25 00:00:00 EST 1989 · J. Biol. Chem.; (United States)

OSTI ID:6155709

Capasso, J M; Keenan, T W; Abeijon, C; Hirschberg, C B

The occurrence of phosphorylated secretory proteins such as caseins and vitellogenin and the recent characterization of phosphorylated proteoglycans, in the xylose and protein core, has raised the question of where in the cell and how this phosphorylation occurs. Previous studies have described a casein kinase activity in the lumen of the Golgi apparatus and this organelle as the site of xylose addition to the protein core of proteoglycans. We now report the translocation in vitro of ATP into the lumen of rat liver and mammary gland Golgi vesicles which are sealed and have the same membrane topographical orientation as in vivo. The entire ATP molecule was translocated into the lumen of the Golgi vesicles; this was established by using ATP radiolabeled with tritium in the adenine and gamma-/sup 32/P. Translocation was temperature dependent and saturable, with an apparent Km of 0.9 microM and Vmax of 58 pmol/mg protein/min. Preliminary evidence suggests that translocation of ATP into the vesicles' lumen is coupled to exit of AMP from the lumen. Following translocation of ATP into the lumen of the vesicles, proteins were phosphorylated.

• Research Organization: Univ. of Massachusetts Medical Center, Worcester (USA)
• OSTI ID: 6155709
• Journal Information: J. Biol. Chem.; (United States), Vol. 264:9
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ATP
MEMBRANE TRANSPORT
PROTEINS
PHOSPHORYLATION
AMP
CELL MEMBRANES
IN VITRO
LIVER
MAMMARY GLANDS
MITOCHONDRIA
ORGANOIDS
PHOSPHOPROTEINS
PHOSPHORUS 32
RATS
TEMPERATURE DEPENDENCE
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CELL CONSTITUENTS
CHEMICAL REACTIONS
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
GLANDS
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
MAMMALS
MEMBRANES
NUCLEI
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
PHOSPHORUS ISOTOPES
RADIOISOTOPES
RODENTS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques