title: Cell-free protein synthesis by kidney from the aging female Fischer F344 rat.
abstract: This is the first report to describe and characterize a cell-free protein synthesis system derived from kidney tissue. The optimum conditions for [3H]-valine incorporation into protein by the post-mitochondrial supernatant from whole kidneys were found to be: pH 6.9, 7.5 mM MgCl2, 150 mM KCl, 10 mM ATP, and 2 mM GTP. The cell-free protein-synthetising activities of kidneys isolated from 4.5-, 7.5-, 22-, and 31-month-old female Fischer F344 rats were measured using the post-mitochondrial supernatant. A 73-87% decrease in cell-free protein synthesis was observed between 4.5 and 31 months of age. Both the cell sap and microsomal fractions of the kidney post-mitochondrial supernatant from old rats were less active in protein synthesis than these fractions from the kidneys of young rats. No age-related change in the activity of RNAase in the kidney post-mitochondrial supernatant was observed. Kidney ribosomes stripped of endogenous mRNA were found to be active in poly(uridylic acid)-directed polyphenylalanine synthesis. The effect of aging on the fidelity of translation was determined by measuring poly(uridylic acid)-directed [14C]-phenylalanine and [3H]leucine incorporation by kidney ribosomes isolated from rats of various ages. No age-related change in the fidelity of poly(uridylic acid) translation by kidney ribosomes was observed.
mesh_terms: D000375:Aging; D000818:Animals; D002474:Cell-Free System; D005260:Female; D007668:Kidney / Q000378:metabolism*; D008274:Magnesium; D008861:Microsomes / Q000378:metabolism; D010649:Phenylalanine / Q000378:metabolism; D011072:Poly U / Q000378:metabolism; D011188:Potassium; D014176:Protein Biosynthesis; D051381:Rats; D011916:Rats, Inbred F344; D012260:Ribonucleases / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D014633:Valine / Q000378:metabolism
chemical_list: D011072:Poly U; D010649:Phenylalanine; D012260:Ribonucleases; D014633:Valine; D008274:Magnesium; D011188:Potassium