1 alpha,25-Dihydroxyvitamin D-induced modification of a cytosolic protein in embryonic chick intestine.
Two-dimensional electrophoresis together with radiolabeling experiments was used to examine cytosolic proteins of embryonic chick duodenum for responses to 1,25-dihydroxyvitamin D3. 1,25-Dihydroxyvitamin D3 caused a striking decrease in [3H]leucine content of an 18,000-dalton protein (approximate pI, 5.1) after a 10-min pulse with radioisotope followed by a 4-h chase. Decreased [14C]leucine content of the same protein was also observed at various times following 1,25-dihydroxyvitamin D3 addition to culture media; a significant decrease in radiolabel incorporation occurred within 30 min after addition of the hormone. The results argue that 1,25-dihydroxyvitamin D3 causes either a decreased synthesis rate or a post-translational modification of this protein. This change joins the biosynthesis of calcium-binding protein as an early event in the response of chick embryonic intestine to 1,25-dihydroxyvitamin D3.
D000818:Animals; D002117:Calcitriol / Q000494:pharmacology*; D002642:Chick Embryo; D003600:Cytosol / Q000032:analysis*; D003720:Densitometry; D005470:Fluorometry; D007422:Intestines / Q000166:cytology / Q000196:embryology*; D007930:Leucine / Q000032:analysis; D011506:Proteins / Q000032:analysis*; D013997:Time Factors
D011506:Proteins; D002117:Calcitriol; D007930:Leucine