Targeting specific proteins for lysosomal proteolysis.
A class of cytosolic proteins has been identified that are degraded faster (have shorter half-lives) in human diploid fibroblasts deprived of serum. In RNase A, a model protein used for these studies, a pentapeptide comprising amino acids 7-11, Lys-Phe-Glu-Arg-Gln or KFERQ, is responsible for its enhanced degradation. The cytosolic proteins that are degraded faster during serum deprivation are recognized by an antiKFERQ antibody and, therefore, probably contain variations of the KFERQ motif. These cytosolic proteins are degraded in lysosomes. Transport into lysosomes in vitro is stimulated by ATP and the heat shock cognate protein of 73 kDa (hsc73).
Olson
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TS
Department of Physiology, Tufts University School of Medicine, Boston, MA 02111.
Terlecky
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Dice
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JF
D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D001693:Biological Transport, Active; D002460:Cell Line; D003600:Cytosol / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D008247:Lysosomes / Q000378:metabolism*; D008969:Molecular Sequence Data; D010447:Peptide Hydrolases / Q000378:metabolism*; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D012259:Ribonuclease, Pancreatic / Q000737:chemistry / Q000378:metabolism
D006360:Heat-Shock Proteins; D011506:Proteins; D000255:Adenosine Triphosphate; D012259:Ribonuclease, Pancreatic; D010447:Peptide Hydrolases