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- Delis, Costas, et al.
(author)
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AtHESPERIN : a novel regulator of circadian rhythms with poly(A)-degrading activity in plants
- 2016
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In: RNA Biology. - : Informa UK Limited. - 1547-6286 .- 1555-8584. ; 13:1, s. 68-82
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Journal article (peer-reviewed)abstract
- We report the identification and characterization of a novel gene, AtHesperin (AtHESP) that codes for a deadenylase in Arabidopsis thaliana. The gene is under circadian clock-gene regulation and has similarity to the mammalian Nocturnin. AtHESP can efficiently degrade poly(A) substrates exhibiting allosteric kinetics. Size exclusion chromatography and native electrophoresis coupled with kinetic analysis support that the native enzyme is oligomeric with at least 3 binding sites. Knockdown and overexpression of AtHESP in plant lines affects the expression and rhythmicity of the clock core oscillator genes TOC1 and CCA1. This study demonstrates an evolutionary conserved poly(A)-degrading activity in plants and suggests deadenylation as a mechanism involved in the regulation of the circadian clock. A role of AtHESP in stress response in plants is also depicted.
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| 2. |
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| 3. |
- Nilsson, Per, et al.
(author)
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A multifunctional RNA recognition motif in poly(A)-specific ribonuclease with cap and poly(A) binding properties
- 2007
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In: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 282:45, s. 32902-32911
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Journal article (peer-reviewed)abstract
- Poly(A)-specific ribonuclease (PARN) is an oligomeric, processive and cap-interacting 3' exoribonuclease that efficiently degrades mRNA poly(A) tails. Here we show that the RNA recognition motif (RRM) of PARN harbors both poly(A) and cap binding properties, suggesting that the RRM plays an important role for the two critical and unique properties that are tightly associated with PARN activity, i.e. recognition and dependence on both the cap structure and poly(A) tail during poly(A) hydrolysis. We show that PARN and its RRM have micromolar affinity to the cap structure by using fluorescence spectroscopy and nanomolar affinity for poly(A) by using filter binding assay. We have identified one tryptophan residue within the RRM that is essential for cap binding but not required for poly(A) binding, suggesting that the cap- and poly(A)-binding sites associated with the RRM are both structurally and functionally separate from each other. RRM is one of the most commonly occurring RNA-binding domains identified so far, suggesting that other RRMs may have both cap and RNA binding properties just as the RRM of PARN.
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