The effects of amino acids on protein degradation and translocation of non-histone proteins to the nucleus in lymphocytes.
Tryptophan, phenylalanine and leucine have two parallel effects in cultured lymphocytes, they inhibit cellular proteolysis and increase the translocation of non-histone proteins to the nucleus. The latter is associated with an increased cellular binding of [3H]actinomycin D, indicating an altered structure of chromatin. The amino acids also inhibit the cellular uptake of [3H]chloroquine, suggesting that inhibited protein degradation is lysosomal. Several amine catabolites of tryptophan and phenylalanine, some of which are known to play a role as biogenic amines, have similar actions, and can explain, at least in part, the effects of their parent amino acids. Fractionation of the nuclear 3H-labeled non-histone proteins according to pH 2.5-6.5 shows that such proteins with a high rate of degradation in untreated cells correspond to the 3H-labeled non-histone proteins with a high rate of translocation in tryptophan treated cells. These data suggest that the degradation and the translocation of the non-histone proteins are linked and that the increased translocation of the non-histone proteins to the nucleus may be the consequence of inhibited lysosomal degradation of these proteins by the amino acids.
D000596:Amino Acids / Q000378:metabolism; D001692:Biological Transport; D002467:Cell Nucleus / Q000378:metabolism*; D002478:Cells, Cultured; D002738:Chloroquine / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D003609:Dactinomycin / Q000378:metabolism; D006801:Humans; D007700:Kinetics; D007930:Leucine / Q000494:pharmacology*; D008214:Lymphocytes / Q000378:metabolism*; D010649:Phenylalanine / Q000494:pharmacology*; D014176:Protein Biosynthesis; D011506:Proteins / Q000378:metabolism*; D014316:Tritium; D014364:Tryptophan / Q000494:pharmacology*
D000596:Amino Acids; D002868:Chromosomal Proteins, Non-Histone; D011506:Proteins; D014316:Tritium; D003609:Dactinomycin; D010649:Phenylalanine; D002738:Chloroquine; D014364:Tryptophan; D007930:Leucine