Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0220723 (PCA)
 4,687 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thyrotrophin (TSH) regulates the biosynthesis of thyroid protein and RNA. This action is mediated by adenylate cyclase and cycl AMP. In the present study the action of cyclic GMP and cyclic CMP was investigated in beef slices. Both cyclic AMP and cyclic GMP significantly increased the incorporation of [3H]uridine into RNA. These effects were blocked by actinomycin D, suggesting that their action is located at a preor at a transcriptional step. The PCA soluble fraction radioactivity followed in parallel with tha variations observed in the RNA fraction, supporting the view that cyclic nucleotides may regulate RNA by modulating the nucleotide precursors pool. Cyclic CMP in concentrations between 0.35 to 1.5 mM progressively decreased the RNA labelling, and the values of the PCA soluble radioactivity again followed those of RNA. Furthermore, cyclic CMP also blocked the in vitro stimulatory action of cyclic AMP on the incorporation of [3H]leucine into protein, and of [3H]uridine into RNA. The present results provide the first information on the action of cyclic AMP on RNA synthesis and suggest that negative signals may also play a part in the regulation of thyroid function.
 ...
PMID:Action of cyclic nucleotides on protein and RNA synthesis in the thyroid. 18 48

1. Lyophilized crude rRNA from trout (Salmo gairdneri R.) liver was composed (w/w) of 2.9% protein, traces of DNA and glycogen, 13% water and 83% pure rRNA. The RNA content was derived from the discrepancy between effectively found (8.1%, w/w) and theoretical phosphorus content (9.6%, w/w). 2. The theoretical phosphorus content was calculated on the basis of the molar distribution of nucleotides in rRNA (UMP:GMP:AMP:CMP = 24.7%:30%:19.5%:25.8%), established upon cation exchange chromatography of alkali-degraded crude rRNA. 3. The extinction coefficient (corrected for moisture and none-ribonucleic acid contaminants) of pure rRNA in 0.2 N PCA after digestion in 0.3 N KOH at 37 degrees C for 90 min is 361 in terms of E1%260. That of undegraded, pure rRNA in water amounts to 279.
 ...
PMID:Specific UV-absorbancy of pure rRNA isolated from trout liver as a standard for the quantification of ribonucleic acid from fish tissues. 366 18