scholarly journals Inorganic phosphate, arsenate, and vanadate enhance exonuclease transcript cleavage by RNA polymerase by 2000-fold

2018 ◽  
Vol 115 (11) ◽  
pp. 2746-2751 ◽  
Author(s):  
Max E. Gottesman ◽  
Arkady Mustaev
Keyword(s):  
Water Molecule ◽  
Rna Polymerase ◽  
Inorganic Phosphate ◽  
Cellular Protein ◽  
Rna Cleavage ◽  
Exonuclease Activity ◽  
Nascent Transcript ◽  
Inorganic P ◽  
Biochemical Pathways ◽  
Transcript Cleavage

Inorganic Pi is involved in all major biochemical pathways. Here we describe a previously unreported activity of Pi. We show that Pi and its structural mimics, vanadate and arsenate, enhance nascent transcript cleavage by RNA polymerase (RNAP). They engage an Mg2+ ion in catalysis and activate an attacking water molecule. Pi, vanadate, and arsenate stimulate the intrinsic exonuclease activity of the enzyme nearly 2,000-fold at saturating concentrations of the reactant anions and Mg2+. This enhancement is comparable to that of specialized transcript cleavage protein factors Gre and TFIIS (3,000- to 4,000-fold). Unlike these protein factors, Pi and its analogs do not stimulate endonuclease transcript cleavage. Conversely, the protein factors only marginally enhance exonucleolytic cleavage. Pi thus complements cellular protein factors in assisting hydrolytic RNA cleavage by extending the repertoire of RNAP transcript degradation modes.

scholarly journals AT-rich sequence elements promote nascent transcript cleavage leading to RNA polymerase II termination

2012 ◽  
Vol 41 (3) ◽  
pp. 1797-1806 ◽  
Author(s):  
Eleanor White ◽  
Kinga Kamieniarz-Gdula ◽  
Michael J. Dye ◽  
Nick J. Proudfoot
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Nascent Transcript ◽  
Transcript Cleavage ◽  
Sequence Elements

scholarly journals Yeast and Human RNA Polymerase II Elongation Complexes: Evidence for Functional Differences and Postinitiation Recruitment of Factors

2003 ◽  
Vol 2 (2) ◽  
pp. 318-327 ◽  
Author(s):  
Timothy S. Pardee ◽  
Mohamed A. Ghazy ◽  
Alfred S. Ponticelli
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Gradient Centrifugation ◽  
Sedimentation Coefficient ◽  
Exonuclease Activity ◽  
Nascent Transcript ◽  
Dna Templates ◽  
Functional Differences ◽  
Nuclear Extracts ◽  
Nuclear Factors

ABSTRACT Immobilized DNA templates, glycerol gradient centrifugation, and native gel analysis were utilized to isolate and compare functional RNA polymerase II (RNAPII) elongation complexes from Saccharomyces cerevisiae and human cell nuclear extracts. Yeast elongation complexes blocked by incorporation of 3′-O-methyl-GTP into the nascent transcript exhibited a sedimentation coefficient of 35S, were less tightly associated to the template than their human counterparts, and displayed no detectable 3′-5′ exonuclease activity on the associated transcript. In contrast, blocked human elongation complexes were more tightly bound to the template, and multiple forms were identified, with the largest exhibiting a sedimentation coefficient of 60S. Analysis of the associated transcripts revealed that a subset of the human elongation complexes exhibited strong 3′-5′ exonuclease activity. Although isolated human preinitiation complexes were competent for efficient transcription, their ability to generate 60S elongation complexes was strikingly impaired. These findings demonstrate functional and size differences between S. cerevisiae and human RNAPII elongation complexes and support the view that the formation of mature elongation complexes involves recruitment of nuclear factors after the initiation of transcription.

scholarly journals Assessment of Inorganic Phosphate Intake by the Measurement of the Phosphate/Urea Nitrogen Ratio in Urine

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 292
Author(s):  
María Victoria Pendón-Ruiz de Mier ◽  
Noemí Vergara ◽  
Cristian Rodelo-Haad ◽  
María Dolores López-Zamorano ◽  
Cristina Membrives-González ◽  
...  
Keyword(s):  
Inorganic Phosphate ◽  
Daily Intake ◽  
Cross Sectional Study ◽  
Normal Serum ◽  
Dietary Recommendations ◽  
Clinical Practices ◽  
Cross Sectional ◽  
Urea Nitrogen ◽  
Inorganic P ◽  
Nitrogen Ratio

In chronic kidney disease (CKD) patients, it would be desirable to reduce the intake of inorganic phosphate (P) rather than limit the intake of P contained in proteins. Urinary excretion of P should reflect intestinal absorption of P(inorganic plus protein-derived). The aim of the present study is to determine whether the ratio of urinary P to urinary urea nitrogen (P/UUN ratio) helps identify patients with a high intake of inorganic P.A cross-sectional study was performed in 71 patients affected by metabolic syndrome with CKD (stages 2–3) with normal serum P concentration. A 3-day dietary survey was performed to estimate the average daily amount and the source of P ingested. The daily intake of P was 1086.5 ± 361.3 mg/day; 64% contained in animal proteins, 22% in vegetable proteins, and 14% as inorganic P. The total amount of P ingested did not correlate with daily phosphaturia, but it did correlate with the P/UUN ratio (p < 0.018). Patients with the highest tertile of the P/UUN ratio >71.1 mg/g presented more abundant inorganic P intake (p < 0.038).The P/UUN ratio is suggested to be a marker of inorganic P intake. This finding might be useful in clinical practices to identify the source of dietary P and to make personalized dietary recommendations directed to reduce inorganic P intake.

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