Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.1 (RNase)
 16,360 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pseudomonas aeruginosa strain P15 produces not only pyocin R1 and phage PS10, but also a substance having a flexuous rod structure, the nature of which is so far unknown. A variant strain (P15--40) was obtained which produced these flexuous particles more effectively than the original strain, and the particles were purified to homogeneity and investigated. Several strains of P. aeruginosa were found to be killed by the particles. It was concluded that the flexuous rod-like particles are not related to pyocin R1 or phage PS10, but represent a new pyocin, which we have designated as pyocin F1. Pyocin F1 showed a different action spectrum and a different pattern on SDS-polyacrylamide gel electrophoresis from either pyocin R1 or phage PS10. The killing activity of pyocin F1 was of single-hit type. The activity was not affected by anti-R1, anti-R1-core or anti-PS10, or by DNase, RNase, pronase or trypsin, but was completely destroyed by treatment at 70 degrees C for 10 min. Some cofactor was required for the adsorption of this pyocin on sensitive bacteria. Another flexuous bacteriocin was also found and named pyocin F2.
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PMID:Biochemical properties of a new flexuous bacteriocin, pyocin F1, produced by Pseudomonas aeruginosa. 10 91

The spatial and temporal patterns of expression and content of bFGF during postnatal development of the retina were established in C57BL/6J mice. Western blot analysis, using an anti-rodent bFGF antibody, shows multiple molecular weights of 18, 20.5, and 22 kDa of bFGF protein isolated from the adult retina. A bioassay indicates that this putative basic fibroblast growth factor (bFGF) stimulates proliferation of BALB/c 3T3 fibroblasts in a dose-dependent manner identical to an authentic bFGF standard. Immunocytochemistry reveals that bFGF immunoreactivity is located primarily in the immature photoreceptors during postnatal development and is associated with the photoreceptor outer segment/interphotoreceptor matrix complex in the adult retina. bFGF mRNA expression pattern and levels were evaluated using mouse bFGF riboprobes with in situ hybridization and quantitative ribonuclease protection assay. bFGF mRNA expression is not detectable in the retina until Postnatal Day 10 (P10), although high levels of bFGF mRNA signals were consistently observed in astrocytes in the optic disc at all postnatal ages examined. From P10 to the adult stage, bFGF mRNA was localized mainly to the photoreceptor inner segments, and the bFGF mRNA levels were approximately the same at P10 and in the adult retina. The patterns of retinal bFGF expression and content during normal development established above were compared to these parameters in the retina of rd (C57BL/6J rd/rd), a spontaneous mouse mutant in which photoreceptors degenerate shortly after birth. More bFGF immunoreactivity was detected in the outer retina during photoreceptor degeneration than was present in normal photoreceptors at equivalent ages. Densitometry measurements indicate that the level of immunoreactivity is 56% to 1.8-fold higher in rd than in the normal retina between P6 and P10, respectively. This is at least partially due to elevated bFGF mRNA expression in rd retinas during photoreceptor degeneration. In situ hybridization showed more intense bFGF mRNA hybridization signals in rd photoreceptors from P10 to P15, and RNase protection assay demonstrated much higher hybridization signals in rd retinas from P6 to P10 than in the normal retinas at these stages. More bFGF mRNA hybridization signals were also present in some cells in the inner nuclear layer following photoreceptor cell death in the rd retina but were only weakly evident in the inner nuclear layer in the normal adult retina. These results provide the first evidence that a naturally occurring neuronal degeneration is accompanied by elevated expression of bFGF in degenerating neurons prior to cell death.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Basic fibroblast growth factor in retinal development: differential levels of bFGF expression and content in normal and retinal degeneration (rd) mutant mice. 775 Jun 36

In the experiments here, the developmental expression of the functional Ca(2+)-independent, depolarization-activated K+ channel currents, Ito and IK, and of the voltage-gated K+ channel (Kv) alpha subunits, Kv1.2, Kv1.4, Kv1.5, Kv2.1, and Kv4.2 in rat ventricular myocytes were examined quantitatively. Using the whole-cell patch clamp recording method, the properties and the densities of Ito and IK in ventricular myocytes isolated from postnatal day 5 (P5), 10 (P10), 15 (P15), 20 (P20), 25 (P25), 30 (P30), and adult (8-12 wk) rats were characterized and compared. These experiments revealed that mean Ito densities increase fourfold between birth and P30, whereas IK densities vary only slightly. Neither the time- nor the voltage-dependent properties of the currents vary measurably, suggesting that the subunits underlying functional Ito and IK channels are the same throughout postnatal development. In parallel experiments, the developmental expression of each of the voltage-gated K+ channel alpha subunits, Kv1.2, Kv1.4, Kv1.5, Kv2.1, and Kv4.2, was examined quantitatively at the mRNA and protein levels using subunit-specific probes. RNase protection assays revealed that Kv1.4 message levels are high at birth, increase between P0 and P10, and subsequently decrease to very low levels in adult rat ventricles. The decrease in message is accompanied by a marked reduction in Kv1.4 protein, consistent with our previous suggestion that Kv1.4 does not contribute to the formation of functional K+ channels in adult rat ventricular myocytes. In contrast to Kv1.4, the mRNA levels of Kv1.2, Kv1.5, Kv2.1, and Kv4.2 increase (three- to five-fold) between birth and adult. Western analyses, however, revealed that the expression patterns of these subunits proteins vary in distinct ways: Kv1.2 and Kv4.2, for example, increase between P5 and adult, whereas Kv1.5 remains constant and Kv2.1 decreases. Throughout development, therefore, there is a mismatch between the numbers of Kv alpha subunits expressed and the functional voltage-gated K+ channel currents distinguished electrophysiologically in rat ventricular myocytes. Alternative experimental approaches will be required to define directly the Kv alpha subunits that underlie functional voltage-gated K+ channels in these (and other) cells. In addition, the finding that Kv alpha subunit protein expression levels do not necessarily mirror mRNA levels suggests that caution should be exercised in attempting functional interpretations of observed changes in mRNA levels alone.
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PMID:Developmental analysis reveals mismatches in the expression of K+ channel alpha subunits and voltage-gated K+ channel currents in rat ventricular myocytes. 892 66

The release of GnRH peptide from neuroterminals in the median eminence increases during postnatal development. We were interested in determining the biosynthetic component contributing to the regulation of GnRH decapeptide levels, and ascertaining the molecular mechanism for these changes. Male and female C57bl/6 mice, from embryonic day (E)16 through postnatal day (P)60, were killed, and the preoptic area-anterior hypothalamus was dissected out. Cytoplasmic and nuclear RNA were extracted separately. Levels of GnRH messenger RNA (mRNA) and primary transcript were quantitated in individual preoptic area-anterior hypothalamus cytoplasmic and nuclear fractions, respectively, by ribonuclease protection assays. Serum LH levels were assayed by RIA. GnRH mRNA levels in the cytoplasm increased gradually and significantly during postnatal development in both males and females, reaching a peak at P55 in females and P40 in males. GnRH primary transcript levels in the nucleus, an index of GnRH gene transcription, changed in a completely different manner developmentally, and they differed between male and female mice. GnRH primary transcript levels in males were quite low until P5, when they underwent an increase of approximately 4-fold, between P5 and P7. They continued to increase through P15, at which time they reached adult levels. In females, GnRH primary transcript levels were high at E16, decreased to a nadir at P5, and then underwent an increase of approximately 5-fold to P7, which were comparable with adult levels. The large and sexually dimorphic changes in GnRH primary transcript between E16 and P7, in the absence of similar changes in GnRH mRNA, suggest that differential mechanisms, such as gene transcription and mRNA stability, play a role in determining levels of GnRH mRNA at different stages of development.
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PMID:Mechanisms for the regulation of gonadotropin-releasing hormone gene expression in the developing mouse. 1021 81

Thyroid hormone (TH) plays a critical role in normal cerebellar development. However, the molecular mechanisms of TH action in the developing cerebellum are not fully understood. This action could be exerted in part through brain-derived neurotropic factor (BDNF), as cerebellar BDNF messenger RNA (mRNA) expression is lower, and replacement of BDNF partially reverses the abnormal neurogenesis in the hypothyroid rat. The rat BDNF gene consists of four noncoding exons (exons I-IV), each of which is linked to a different promoter, and a protein-coding exon (exon V). To study promoter-specific regulation of the BDNF gene by TH, ribonuclease protection assay of each exon mRNA was performed using total developing rat cerebellar RNA. During cerebellar development, all exon mRNAs were detected, but with different expression patterns; among noncoding exon mRNAs, exon II mRNA was the most abundant. Daily TH replacement induced a 3-fold increase in exon II mRNA on postnatal day (P) 15. On P30, exon II mRNA was still much greater in the TH-replaced animal. Exon I mRNA was detected on P2 and P7. However, in contrast to exon II mRNA, TH treatment suppressed the expression of exon I mRNA on P2. Exon III and IV mRNAs were not detected on P2 and P7, but small amounts were observed starting on P15 in TH-replaced animals. They were not detected by P30 in hypothyroid animals. In contrast, in the cerebral cortex, although all exons are differentially regulated during development, the expression of each mRNA was not significantly altered by TH. These results indicate that TH regulates BDNF gene expression in a promoter-, developmental stage-, and brain region-specific manner, which may play an important role in region- and stage-specific regulation of brain development by TH.
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PMID:Promoter-specific regulation of the brain-derived neurotropic factor gene by thyroid hormone in the developing rat cerebellum. 1046 64

The preoptic regulatory factor genes, PORF-1 and PORF-2, are expressed in the rat brain in a regional-, age- and gender-dependent fashion. They are also expressed in the testis, where PORF-2 mRNA localizes to dividing germ cells while PORF-1 mRNA is associated with newly differentiated sperm. This suggests that PORF-1 and PORF-2 may play distinct roles in cell growth and differentiation. Moreover, the two preoptic regulatory factors are also highly expressed in the immature and mature rat hypothalamus, and their expression is modulated by gonadal hormones. Therefore, in the present study we investigated the expression of these two factors in neuroendocrine regions of the developing rat brain by addressing the following questions. First, are PORF-1 and PORF-2 mRNAs expressed during perinatal development in the preoptic area-anterior hypothalamus (POA-AH) and medial basal hypothalamus (MBH), and how do their levels vary? Second, are there gender differences in their expression? We also compared expression of the PORF mRNAs with those of neuropeptide Y (NPY) and gonadotropin-releasing hormone (GnRH), which play critical neuroendocrine roles, in these brain regions. PORF-1, PORF-2, and NPY mRNAs in the POA-AH and MBH, and GnRH mRNA in the POA-AH, were quantified by RNase protection assay at embryonic day (E) 18-19, and postnatal days (P) 0, 5, 10 and 15 in male and female rats. The results show that the four neuropeptide genes are regulated differentially during the perinatal-prepubertal period. PORF-1 mRNA shows age-related increases in expression from E18-E19 to P15 in POA-AH and MBH, without significant gender differences. In contrast, PORF-2 mRNA shows both age and gender differences in expression in these brain regions, with decreases occurring during the same time period in development. NPY mRNA increases similarly in males and females with age in POA-AH and MBH during this period. GnRH mRNA does not change during this period. Taken together with previous studies, the results suggest possible roles for PORF-1 and NPY in the pubertal process, since their expression is maximal from the prepubertal to the early pubertal period. The observation of highest levels of expression of PORF-2 in embryonic neuroendocrine tissues suggests a possible involvement of this neuropeptide in prenatal/neonatal developmental events.
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PMID:Perinatal developmental changes in expression of the neuropeptide genes preoptic regulatory factor-1 and factor-2, neuropeptide Y and GnRH in rat hypothalamus. 1058 30

These studies were performed to determine the developmental expression pattern of neurotrophic factor (NTF: nerve growth factor (betaNGF), brain-derived neurotrophic factor (BDNF), glial-derived neurotrophic factor (GDNF), ciliary neurotrophic factor (CNTF), neurotrophin-3 (NT-3) and NT-4 mRNA and NGF, NT-3 and NT-4 protein in the urinary bladder of the postnatal Wistar rat. It was hypothesized that NTFs may contribute to the development of the spinobulbospinal micturition reflex that represents the adult micturition pattern. Changes in NTF mRNA or protein expression in the urinary bladder at the time of development of the mature micturition reflex (postnatal days (P) 16-18) may suggest an involvement of target-derived NTFs in this maturation process. Developmental ages, prior to (P5, P10, P15) or following (P20, P30, adult P90) the development of the spinobulbospinal micturition reflex were selected and the urinary bladder was analyzed for levels of neurotrophic factor mRNA or protein. Results from ribonuclease protection assays demonstrated a similar developmental pattern among each neurotrophic factor examined. Neurotrophic factor mRNA levels increased by P10 and reach a maximum by P15. Subsequently, NTF mRNA levels declined to adult levels that were less than the earliest postnatal time examined (P5). NTF mRNA expression was significantly (p</=0.05-0.001) greater at P10, P15, P20 and P40 (NT-4 mRNA) compared to adult levels for each NTF examined except GDNF mRNA. In general, NGF, NT-3 and NT-4 urinary bladder protein levels in early postnatal development, as determined by ELISA, were similar when compared to the corresponding mRNA expression. Differences in the correlation between NT-3 and NT-4 mRNA and protein expression were demonstrated in the adult urinary bladder where significantly (p</=0. 001) greater levels of protein were revealed despite relatively low abundance of NT-3 and NT-4 mRNA. The developmental expression pattern (maximum expression at the second to third postnatal week) of NTFs in the urinary bladder is consistent with a potential role in the development of the spinobulbospinal reflex. Relatively high expression of NT-3 and NT-4 protein in the adult urinary bladder suggests a potential importance of these factors in the adult lower urinary tract.
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PMID:Developmental expression of urinary bladder neurotrophic factor mRNA and protein in the neonatal rat. 1067 71

A sensitive RNase protection assay was employed to determine the levels of mRNA encoding the GluR1 subunit flip and flop isoforms in the chick optic tectum and forebrain. We found that the flip GluR1 mRNA predominates in the forebrain, whereas the flop variant is more strongly expressed in the optic tectum. A temporal analysis of GluR1 variants in the embryonic and adult chick brain revealed that the flip isoform is more highly expressed at E12 than at P15-21, whereas mRNA levels of the flop isoform are higher at P15-21 than at E12. To study the effect of deafferentation on GluR1 expression, unilateral retinal lesions were performed. Two days later the mRNA levels of GluR1 flip and flop variants were decreased in the deafferented tectum, especially for the flop isoform. However, 7 days after the lesion, the mRNA levels of both GluR1 isoforms were increased, especially for the flip isoform. These results reveal an important control of the retinal input upon the expression of the different GluR1 isoforms. Furthermore, they indicate a differential spatial and temporal regulation of the flip and flop splice variants, suggesting the existence of a mechanism regulating differential splicing or possibly differential RNA stability.
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PMID:Retinal lesions induce differential changes in the expression of flip and flop isoforms of the glutamate receptor subunit GluR1 in the chick optic tectum. 1076 10

RNA sequences required for assembly into rod-shaped virions of RNA-1 and RNA-2 of Peanut clump virus (PCV) were mapped by testing the ability of different RNA-1 and -2 deletion mutants to be encapsidated in vivo in an RNase-resistant form. Encapsidation of RNA-1 was found to require a sequence domain in the 5'-proximal part of the P15 gene, the 3'-proximal gene of RNA-1. On the other hand, the subgenomic RNA which encodes P15 was not encapsidated, suggesting that other features of RNA-1 are important as well. Two sequences which could drive encapsidation of RNA-2 deletion mutants were located. One was in the 5'-proximal coat protein gene and the other in the P14 gene near the RNA 3' terminus. There were no obvious sequence homologies between the different assembly initiation sequences.
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PMID:Mapping of viral RNA sequences required for assembly of peanut clump virus particles. 1291 80

In Arabidopsis, micro (mi)RNAs and trans-acting (ta-si)RNAs synthesized directly or indirectly through the DICER-LIKE-1 (DCL1) ribonuclease have roles in patterning and hormonal responses, while DCL2,3,4-dependent small-interfering (si)RNAs are mainly involved in silencing of transposable elements and antiviral defense. Viral suppressors of RNA silencing (VSRs) produced by phytoviruses to counter plant defense may perturb plant developmental programs because of the collision of their inhibitory effects with the regulatory action of endogenous miRNAs and ta-siRNAs. This could explain the similar developmental aberrations displayed by Arabidopsis miRNA/ta-siRNA pathway mutants, including dcl1, and by some VSR-expressing plants. Nonetheless, the molecular bases for these morphological aberrations have remained mysterious, and their contribution to viral disease symptoms/virulence unexplored. The extent of VSR inhibitory actions to other types of endogenous small RNAs remains also unclear. Here, we present an in-depth analysis of transgenic Arabidopsis expressing constitutively HcPro, P19 and P15, three unrelated VSRs. We show that VSR expression has comparable, yet modest effects on known miRNA and ta-siRNA target RNA levels, similar to those observed using an hypomorphic dcl1 mutation. However, by combining results of transcriptome studies with deep-sequencing data from immuno-precipitated small RNAs, additional, novel endogenous targets of miRNA and ta-siRNA were identified, unraveling an unsuspected complexity in the origin and scope-of-action of these molecules. Other stringent analyses pinpointed misregulation of the miR167 target AUXIN RESPONSE FACTOR 8 (ARF8) as a major cause for the developmental aberrations exhibited by VSR transgenic plants, but also for the phenotypes induced during normal viral infection caused by the HcPro-encoding Turnip mosaic virus (TuMV). Neither RNA silencing, its suppression by VSRs, nor the virulence/accumulation of TuMV was altered by mutations in ARF8. These findings have important implications for our understanding of viral disease symptoms and small RNA-directed regulation of plant growth/development.
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PMID:Misregulation of AUXIN RESPONSE FACTOR 8 underlies the developmental abnormalities caused by three distinct viral silencing suppressors in Arabidopsis. 2714 83


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