Increased phosphorylation of specific rat cardiac and retinal proteins in taurine-depleted animals: isolation and identification of the phosphoproteins.
Partial depletion of the tissue levels of taurine in the alive animal stimulates in vitro phosphorylation of both an approximately 20 kDa (94%) and an approximately 44 kDa (85%) protein present in subcellular fractions of the rat retina and heart. Tissue levels of taurine were reduced by feeding the animals 1.5% guanidinoethanesulfonic acid (GES) in their drinking water for 6 weeks. The increase in the in vitro phosphorylation of both the approximately 20 kDa and approximately 44 kDa proteins was reversed when the animals were subsequently given 1.5% taurine in their drinking water for an additional 6 weeks. Isolation, purification, tryptic digestion, and peptide sequence analysis of the retinal approximately 20 kDa phosphoprotein suggest that it is histone H2B. However, the results are ambiguous due to an impurity (< 25%) in the retinal preparation. Sequence analysis of the approximately 44 kDa phosphoprotein indicates that it is pyruvate dehydrogenase.
Lombardini
J B
JB
Department of Pharmacology, Texas Tech University Health Sciences Center, Lubbock 79430, USA.
D000818:Animals; D006321:Heart; D009206:Myocardium / Q000378:metabolism*; D010750:Phosphoproteins / Q000302:isolation & purification / Q000378:metabolism*; D010766:Phosphorylation; D051381:Rats; D012160:Retina / Q000378:metabolism*; D013654:Taurine / Q000378:metabolism*
D010750:Phosphoproteins; D013654:Taurine