Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.1 (S1 nuclease)
 3,660 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The appearance of the mRNA for the adult fast IIB myosin heavy chain (MHC) was examined during postnatal development of rats using an S1 nuclease assay. In normal rats, a large increase in the adult MHC mRNA began at 6-7 days after birth, whereas daily injections of newborn rats with 3 micrograms of triiodothyronine (T3) resulted in a precocious increase of the mRNA as early as 3 days after birth. Injection of a range of doses of T3 demonstrated that a large effect was obtained between 30 and 300 ng of T3/day/rat. Fast myosin protein was also precociously induced over the same range of T3 doses. This effect was also seen in denervated muscles, and muscles responded similarly to the different doses of T3 whether they were denervated or not. These results suggest that either thyroid hormone or some circulating factors induced by thyroid hormone are limiting factors in controlling the neonatal-to-adult fast MHC transition and that these factors may act directly on muscle tissue.
 ...
PMID:Thyroid hormone induces a nerve-independent precocious expression of fast myosin heavy chain mRNA in rat hindlimb skeletal muscle. 283 75

Regulation of slow troponin C gene expression was examined in both skeletal and cardiac muscle at various stages of development in chicken. The steady-state levels of troponin C mRNA were initially measured by Northern blot analysis. It was observed that the level of troponin C mRNA reached its maximum in both skeletal and cardiac muscle of 16- to 18-day-old embryos. A drop in troponin C mRNA level was observed just prior to hatching. The level of actin mRNA, myosin heavy chain mRNA, and mRNA for a nonmuscle protein, vimentin, was also similarly regulated during development of chicken muscles. Further studies were carried out to determine the level of slow troponin C mRNA using nuclease S1 protection analysis. A significant amount of slow troponin C mRNA was found in the skeletal muscle of adult chicken, which predominantly consists of the fast isoform of troponin C. This observation suggests the possibility of post-transcriptional control of slow troponin C synthesis in skeletal muscle. Primary cultures of cardiac myocytes were also used to determine how the troponin C mRNA level is regulated in a culture of cardiac muscle cells. Measurements of the steady-state levels of slow troponin C mRNA by nuclease S1 protection analysis show that it was maximal in 60-h-old cultures. A drop in the level of this mRNA was observed after these cells were maintained in culture for 4 days.
 ...
PMID:Developmentally regulated slow troponin C messenger RNA in chicken skeletal and cardiac muscles. 284 45

We report here the isolation and characterization of cDNA and genomic sequences corresponding to a rat embryonic myosin heavy chain (MHC) protein. This gene, which is present as a single copy in the rat genome, comprises about 25 kilobase pairs of DNA and contains approximately 80% intronic sequences. The embryonic MHC gene belongs to a highly conserved multigene family, and exhibits a high degree of nucleotide and amino acid sequence conservation with other sarcomeric MHC genes from nematode to man. S1 nuclease mapping experiments using cDNA and genomic probes show that this MHC gene is transiently expressed during skeletal muscle development. Its mRNA is detected in fetal skeletal muscle during early development and persists up to 2 weeks after birth with the overlapping expression of neonatal and adult skeletal MHC mRNAs. However, this MHC is not expressed in the adult skeletal muscle with the exception of extraocular muscle fibers. The transient expression during muscle development of the isoform produced by this gene and its sequential replacement by other MHCs raises interesting questions about the mechanism controlling MHC isozyme transitions and the physiological significance of the individual MHCs in muscle fibers.
 ...
PMID:Characterization of cDNA and genomic sequences corresponding to an embryonic myosin heavy chain. 299 40

A human myosin heavy-chain gene, cloned in gamma Charon 4A phage (and as a clone designated lambda gMHC-1), was shown to code for a cardiac myosin heavy chain of the beta-type. The 5' end of the 14,200-base-pair genomic DNA clone is located in the head region of the myosin chain. The 3' end was shown to extent to the COOH terminus and includes the 3'-nontranslated sequence of the corresponding mRNA. The identification of lambda gMHC-1 as coding for a cardiac beta-myosin heavy chain was achieved by heteroduplex mapping using genomic cardiac myosin heavy-chain DNA of rabbit as a probe and, furthermore, by DNA sequence analysis of three selected subregions of the clones DNA including the 3'-nontranslated sequence. It was demonstrated by the S1 nuclease protection technique that the beta-myosin heavy-chain gene is transcribed in human heart muscle. In addition, we have found by the same technique that it is also expressed in human skeletal muscle.
 ...
PMID:Partial characterization of the human beta-myosin heavy-chain gene which is expressed in heart and skeletal muscle. 302 60

A cDNA clone, SMHC-29, encoding the light meromyosin of smooth muscle myosin heavy chain (MHC), was isolated from a rabbit uterus cDNA library constructed in phage lambda gt11. This smooth muscle MHC cDNA demonstrates significant nucleotide and amino acid sequence homologies with known sarcomeric MHC genes from rabbit, rat skeletal, and nematode body wall myosin, and even with nonmuscle MHC gene from a slime mold (Dictyostelium discoideum), suggesting that smooth muscle, striated muscle, and nonmuscle MHC genes diverged from a common ancestor. The deduced amino acid sequences of the smooth muscle light meromyosin show very similar periodic distributions of hydrophobic and charged residues as found for the light meromyosin of striated muscle MHCs together with a high potential for alpha-helical formation, indicating an alpha-helical coiled-coil structure for the smooth muscle light meromyosin sequences. Furthermore, S1 nuclease mapping has revealed that this smooth muscle MHC gene for SMHC-29 is specifically expressed in smooth muscles of vascular and nonvascular types but not in the striated muscles or nonmuscle cells.
 ...
PMID:Characterization of a mammalian smooth muscle myosin heavy chain cDNA clone and its expression in various smooth muscle types. 342 77

A cDNA clone, pVHC1, was isolated from a Syrian hamster heart cDNA library and was compared to the rat alpha (pCMHC21) and beta (pCMHC5) ventricular myosin heavy chain cDNA clones. The DNA sequence and amino acid sequence deducted from the DNA show more homology with pCMHC21 than pCMHC5. This indicates that pVHC1 is an alpha ventricular myosin heavy chain cDNA clone. However, even though pVHC1 shows a high degree of nucleotide and amino acid conservation with the rat myosin heavy chain sequences, the carboxyl-terminal peptide and the 3'-untranslated region are highly divergent and specific for this cDNA clone. There appears to be an amino acid deletion in the 3' end of the hamster alpha myosin heavy chain as compared to the rat alpha myosin heavy chain. S1 nuclease mapping experiments have shown that the mRNA represented by this cDNA clone is scarcely expressed in neonatal development, but its expression increases with age and reaches maximal levels in adult life. This cDNA clone provides a useful tool to follow the myosin heavy chain mRNA changes during development and during the genesis of a cardiomyopathy, an autosomal recessive defect carried by the Syrian hamster.
 ...
PMID:Construction and characterization of the alpha form of a cardiac myosin heavy chain cDNA clone and its developmental expression in the Syrian hamster. 345 74

We have found evidence for two beta-like myosin heavy chains in humans, one cardiac and one skeletal. The cDNA sequences of the cardiac beta myosin heavy chain cDNA clone pHMC3 and the skeletal beta-like myosin heavy chain cDNA clone pSMHCZ, were compared to each other. It was found that the 3' untranslated regions as well as 482 nucleotides specifying the carboxyl coding region, were 100% homologous. Further examination revealed that the skeletal clone pSMHCZ diverges from the human cardiac beta myosin heavy chain cDNA clone pHMC3 at the 5' end. We present evidence in this report which indicates that the cardiac beta myosin heavy chain mRNA is expressed in skeletal muscle tissues. The human cardiac beta myosin heavy chain cDNA clone, pHMC3, which codes for a portion of the light meromyosin section of the myosin heavy chain, was used as a probe for S1 nuclease mapping studies with RNA derived from cardiac tissue, smooth muscle and skeletal muscle tissues consisting of fast-twitch, slow-twitch and mixed fast- and slow-twitch muscle fibres. Two probes were used to examine the expression of the mRNA. One probe (406 nucleotides) constitutes the 3' untranslated region and a portion of the coding region of the beta cardiac myosin heavy chain cDNA clone, which is 100% homologous to pSMHCZ, the skeletal cDNA clone. The other constitutes the majority of the coding region (1017 nucleotides) of the cardiac clone pHMC3 in which the first 216 nucleotides from the labelled end are 100% homologous to the skeletal clone pSMHCZ. In the soleus muscle, which is rich in slow-twitch type I muscle fibres, the expression of the cardiac beta myosin heavy chain mRNA was very prominent. In gastrocnemius muscle, a mixed fibre muscle, the expression of this mRNA was detected to a lesser degree than that for the soleus muscle. In vastus lateralis and vastus medialis, which consist of predominantly type II, fast-twitch fibres, there were trace amounts of the cardiac beta myosin heavy chain mRNA. When expression of this mRNA was tested in smooth muscle tissue none could be detected.
 ...
PMID:Two different forms of beta myosin heavy chain are expressed in human striated muscle. 365 86

We have constructed and isolated a cardiac myosin heavy chain (HC) cDNA clone, pMHC alpha 81, with mRNA from ventricular heart muscle of hyperthyroid rabbits. The clone encodes approximately 480 amino acids of the COOH terminus of light meromyosin and all of the 3' nontranslated region of the corresponding mRNA. Nuclease S1 analyses indicated that the clone is transcribed in hyperthyroid, but not in hypothyroid ventricles and, therefore, corresponds to ventricular alpha-HC mRNA. With probes from the more divergent 3' non-translated region of pMHC alpha 81 and also from selected portions of two previously characterized rabbit cDNA clones ( pMHC alpha 252 and pMHC beta 174), we analyzed the myosin HC mRNAs of atrial, fast skeletal, and slow skeletal muscles by nuclease S1 mapping. In atrial muscle, only one major transcript was detected. The sequence of this transcript was indistinguishable from ventricular alpha-HC mRNA in the 3' nontranslated region and in two coding segments. In contrast, the sequence divergence between the ventricular alpha-HC mRNA and the mRNAs of ventricular beta, fast skeletal, and slow skeletal myosin HCs was clearly detected. There appeared to be, however, considerable homology between coding sequences of ventricular beta and slow skeletal myosin HC mRNAs. The results strongly suggest that rabbit atrial and ventricular alpha-HCs are encoded by the same gene.
 ...
PMID:Expression of rabbit ventricular alpha-myosin heavy chain messenger RNA sequences in atrial muscle. 632 91

We investigated the expression of myosin heavy chain (MHC) isoenzymes in embryonic rat ventricles cultured in the anterior eye chamber of an adult rat. In oculo, these grafts beat and mature in an environment where the hormonal milieu can be manipulated. S1 nuclease protection assays were performed on pooled samples of ventricle grafts and compared to normally growing ventricles. At the time of grafting (embryonic day 12, E-12), 23 +/- 4% of the MHC mRNA was of the alpha isoform. While the proportion of ventricular alpha-MHC mRNA did not increase in utero, embryonic ventricles cultured in oculo showed a rapid increase in the relative amount of alpha-MHC mRNA expression (to 84 +/- 10% by 3 days and 86 +/- 5% by 8 days in oculo). alpha-MHC mRNA expression predominated through 8 weeks of culture in oculo, being 76% at 8 weeks in oculo. Additional experiments were performed to determine whether the rapid conversion to alpha-MHC expression resulted from exposure to adult levels of testosterone or thyroid hormone. Reduction of testosterone exposure to nondetectable levels by host orchiectomy did not affect the rapid conversion to alpha-MHC mRNA expression. Exposure to a hypothyroid milieu (i.e., PTU-treated hosts) decreased but did not prevent the conversion from beta- to alpha-MHC mRNA expression at 8 days in oculo; with 83% of the MHC mRNA being of the alpha isoform in hypothyroid hosts compared to 95% in euthyroid hosts. After 8 weeks of culture in hypothyroid hosts, however, alpha-MHC mRNA expression was undetectable in grafted ventricles. These data suggest that E-12 myocardial grafts respond to the hormonal milieu of an adult rat with rapid conversion from beta- to alpha-MHC mRNA expression and that alpha-MHC expression in early developing heart may show reduced sensitivity to downward modulation by a hypothyroid hormonal milieu.
 ...
PMID:Rapid conversion from beta-MHC to alpha-MHC mRNA expression in embryonic rat ventricle cultured in oculo is not dependent on thyroid hormone or testosterone. 747 87

Adult fast myosin heavy chain (MHC) isoforms are accumulated in fibers of rat hindlimb skeletal muscle which initially contain neonatal MHC at birth. The specific factors controlling these transitions are not known, but in rat and mouse muscle tissue the transition between the neonatal and adult fast MHC proteins does not appear to require continuous innervation. We have reinvestigated the role of innervation in the neonatal-to-adult fast MHC protein and mRNA transitions that occur in developing rat fast-twitch muscles using immunohistochemistry and S1 nuclease mapping. We find that neonatal MHC-containing developing fibers exhibit different responses after denervation at birth regarding the disappearance of neonatal MHC and the accumulation of adult fast MHC isoforms. Immunohistochemistry shows that one fiber population loses neonatal MHC and accumulates adult fast IIB (or possibly IIX) MHC over a period of 2-3 weeks, whereas in the other population neonatal MHC does not decrease nor does the adult fast IIA isoform accumulate to high levels. The results of S1 analysis of mRNAs show that the levels of neonatal MHC mRNA do not decrease in muscles denervated at birth. We also demonstrate that in young adult rats this mRNA is reexpressed in denervated or paralyzed muscles. Since the appearance of IIB mRNA has been previously shown to be nerve-independent (S.D. Russell, N. Cambon, B. Nadal-Ginard, and R.G. Whalen, 1988, J. Biol. Chem. 263, 6370-6374), these results suggest that fibers containing neonatal MHC in rat hindlimb muscles at birth are already differentiated (i.e., preprogrammed) to accumulate either the adult fast IIA or IIB MHC isoforms and that the neonatal-to-adult MHC transitions occurring in these two fiber populations are controlled by different mechanisms.
 ...
PMID:Two types of neonatal-to-adult fast myosin heavy chain transitions in rat hindlimb muscle fibers. 850 Jun 49


<< Previous 1 2