Disease relevance of RNS1

• Cyanobacteria are among the earliest life forms, indicating that the divergence from a common ancestor of nucleotide-sugar epimerases and an mRNA binding protein with ribonuclease activity was ancient [1].

High impact information on RNS1

• Both miRNA and RNA silencing pathways require participation of DICER-LIKE (DCL) ribonuclease III-like enzymes [2].
• Small interfering RNAs (siRNAs) and microRNAs (miRNAs) are processed by the ribonuclease Dicer from distinct precursors, double-stranded RNA (dsRNA) and hairpin RNAs, respectively, although either may guide RNA silencing via a similar complex [3].
• However, two other Pi starvation-responsive genes, AtIPS1 and AtRNS1, are induced more slowly in siz1 seedlings by Pi limitation [4].
• To address these questions, we have investigated the RNS2 gene, which encodes an S-like RNase (RNS2) of Arabidopsis [5].
• They are processed from longer precursor RNAs that fold into stem-loop structures by the ribonuclease Dicer and are thought to regulate gene expression by base pairing with RNAs of protein-coding genes [6].

Biological context of RNS1

• In contrast to what occurs during P(i) starvation, both RNS1 and RNS3 are modestly induced during senescence, indicating that the two stimuli could trigger different signal transduction pathways [7].
• Amino acid sequence, genomic structure and phylogenetic analyses indicated that AhSL28 is most similar to RNS2, an S-like RNase from Arabidopsis thaliana and formed a distinct subclass together with several other S-like RNases within the S-RNase superfamily [8].
• Map-based cloning of AHG2 revealed that this gene encodes a poly(A)-specific ribonuclease (AtPARN) that is presumed to function in mRNA degradation [9].
• Here, using reverse transcription PCR and ribonuclease protection analysis, we demonstrate that, in addition to the full-length CGS transcript, a deleted form exists in Arabidopsis [10].
• Ribonuclease protection showed tETR mRNA was undetectable in unripe fruit or pre-senescent flowers, increased in abundance during the early stages of ripening, flower senescence, and in abscission zones, and was greatly reduced in fruit of ripening mutants deficient in ethylene synthesis or response [11].

Associations of RNS1 with chemical compounds

• Additionally, the systemic induction appears to be controlled independently of jasmonic acid, and the local induction of RNS1 and the nuclease activities are independent of both JA and oligosaccharide elicitors [12].
• A secondary effect of carotenoid deficiency, both in immutans and in wild-type plants treated with a herbicide that blocks carotenoid synthesis, is an increase in acid ribonuclease activity in white tissue [13].
• Molecular analysis of ethylene biosynthesis was accomplished using cDNAs encoding 1-aminocyclopropane-1-carboxylic acid (ACC) synthase and ACC oxidase in ribonuclease protection assays and in situ hybridizations [14].
• Spinach CSP41, an mRNA-binding protein and ribonuclease, is homologous to nucleotide-sugar epimerases and hydroxysteroid dehydrogenases [1].

Other interactions of RNS1

• These specific antibodies also demonstrated that RNS1 is secreted, whereas RNS2 is intracellular [15].
• The RNS1 gene is sharply induced during starvation for P(i), an effect specific among the major macronutrients, whereas RNS3 transcript levels remain relatively constant [7].
• The corresponding cDNA clone VRN1, encoding an S-like RNase of V. carteri, is the first T(2)/S-like RNase to be cloned from green algae [16].
• Ribonuclease protection experiments showed further that this negative regulation is confined almost exclusively to the shortest, most abundant PHYA transcript, and occurs predominantly in shoots [17].

Analytical, diagnostic and therapeutic context of RNS1

• Molecular cloning of cDNAs encoding ribonuclease-related proteins in Nicotiana glutinosa leaves, as induced in response to wounding or to TMV-infection [18].

References