Biosynthesis and processing of mitochondrial glutaminase
The phosphate-dependent glutaminase is asymmetrically associated with the matrix surface of the inner membrane of rat renal mitochondria. The glutaminase contained within intact mitochondria consists of two peptides that are structurally related. However, in vitro translation of renal poly(A/sup +/)RNA yields a 72 kDa protein that is precipitated by glutaminase specific IgG. HTC hepatoma cells and primary cultures of renal proximal tubular cells were used to determine if the 72 kDa protein is a precursor of the mitochondrial glutaminase. When the cells were incubated with (/sup 35/S)methionine for < 3 min. the predominant immunoprecipitable glutaminase has a M/sub r/=72 kDa. With longer periods of incubation, labeled peptides of M/sub r/ = 68 and 65 kDa were also immunoprecipitated. When cells were pulse labeled in the presence of 5 ..mu..M CCCP, a mitochondrial uncoupler, only the 72 kDa protein is formed. When chased with 10 mM methionine and 10 mM cystamine, an antagonist of CCCP, the 72 kDa protein is processed to the 68 and 65 kDa peptides. This process occurs rapidly at 37/sup 0/C, but is slowed considerably at 10/sup 0/C. Quantitative fluorographic analysis of the immunoprecipitated and separated peptides should establish the temporal sequence and kinetics of formation of the processed forms of the glutaminase. Further studies will be conducted to determine the structural difference between the two peptides and their functional significance.
- Research Organization:
- Univ. of Pittsburgh, PA
- OSTI ID:
- 6374671
- Report Number(s):
- CONF-870644-; TRN: 87-033975
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 46:6; Conference: 78. annual meeting of the American Society of Biological Chemists conference, Philadelphia, PA, USA, 7 Jun 1987
- Country of Publication:
- United States
- Language:
- English
Similar Records
Exercising mammals synthesize stress proteins
Mechanisms of Tl-201 uptake in a tumor cell line
Related Subjects
AMIDASES
BIOSYNTHESIS
FRACTIONATION
PEPTIDES
MOLECULAR STRUCTURE
CELL MEMBRANES
KIDNEYS
METHIONINE
MITOCHONDRIA
PRECURSOR
RATS
SULFUR 35
TRACER TECHNIQUES
AMINO ACIDS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CARBOXYLIC ACIDS
CELL CONSTITUENTS
DAYS LIVING RADIOISOTOPES
DRUGS
ENZYMES
EVEN-ODD NUCLEI
HYDROLASES
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
LIPOTROPIC FACTORS
MAMMALS
MEMBRANES
NON-PEPTIDE C-N HYDROLASES
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANOIDS
ORGANS
PROTEINS
RADIOISOTOPES
RODENTS
SEPARATION PROCESSES
SULFUR ISOTOPES
SYNTHESIS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques