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S Hiremath

Publications and source records attributed to S Hiremath.

12 recordsLinked to original sources
PubMed1999

Cloning and complete sequence characterization of two gypsy moth aminopeptidase-N cDNAs, including the receptor for Bacillus thuringiensis Cry1Ac toxin.

The complete cDNAs corresponding to two distinct gypsy moth (Lymantria dispar) larval gut aminopeptidases, APN1 and lambda APN2, were cloned and sequenced. The 3.4 kilobasepair cDNA of APN1 which encodes a 1017 amino acid prepro-protein corresponds to the previously-identified gypsy moth APN (APN-1) that specifically binds the Cry1Ac delta-endotoxin of Bacillus thuringiensis. Analysis of the primary structure of APN1 revealed a cluster of five potential N-linked glycosylation sites near the N-terminus and a C-terminal sequence characteristic of a putative glycosylphosphatidyl-inositol (GPI) anchor signal sequence. The cDNA of APN1 encodes the N-terminal peptide sequence and nine internal sequences obtained from the purified brush border membrane vesicle Cry1Ac receptor by protein sequencing. The lambda APN2 cDNA encodes a shorter protein with 51% similarity to APN1 that also appears to have a GPI anchor signal sequence. Expression of the APN1 cDNA in a baculovirus vector was confirmed by immunoblotting.

Amino Acid Sequence↗
PubMed1998

Expression of actin in the central nervous system is switched off during diapause in the gypsy moth, Lymantria dispar.

Diapause-regulated proteins were identified in the CNS of pharate 1st instar larvae of the gypsy moth, Lymantria dispar. Expression of two proteins (130kDa and 45kDa) declined at the time of diapause initiation and remained low during diapause. At diapause termination, following exposure to 5 degrees C for at least 60 days, the 45-kDa protein was again highly expressed. Treatment of young pharate larvae with KK-42 averted diapause, and in such larvae, continued synthesis of the 45 kDa protein in the CNS was observed. These results suggest that expression of the 45-kDa protein is strongly down-regulated in the central nervous system (CNS) during diapause. Partial amino acid sequence determination suggested that the 45-kDa protein is actin, and this was confirmed using anti-actin antibodies. RT-PCR using primers designed from the sequence of the gypsy moth midgut actin mRNA indicated that appearance of actin mRNA in the CNS followed the same pattern as that of the 45-kDa protein. The results indicate that diapause controls actin gene expression in the gypsy moth CNS and regulation is at the transcriptional level.

Journal Article↗
PubMed1997

Structure of the gypsy moth vitellogenin gene.

Genomic clones containing the vitellogenin (Vg) gene from the gypsy moth were isolated from two genomic libraries and characterized. The nucleotide sequence of a 16,132 bp region of the gypsy moth genome was determined which included a 3,666 bp region upstream from the transcription initiation site and 499 bp region downstream from the transcribed region. Primer extension analysis was performed to identify the transcription initiation site. Gene sequence confirmed the sequence of VgmRNA recently reported [Hiremath and Lehtoma, J. Insect Biochem. Mol. Biol. (1997) 27:27-35] and indicated that the gypsy moth Vg gene contains seven exons interrupted by six introns. Sequence analysis of the promoter region revealed presence of several motifs associated with sex-specific and developmentally regulated genes in other systems. The nucleotide sequence comparison analyses showed that the gypsy moth Vg gene had considerably similarity with the Bombyx mori Vg gene but not with those from Anthonomous grandis and Aedes aegypti.

Amino Acid Sequence↗
PubMed1997

Complete nucleotide sequence of the vitellogenin mRNA from the gypsy moth: novel arrangement of the subunit encoding regions.

Primary structure analysis and location of introns suggests evolutionary relatedness among vitellogenin (Vg) genes from vertebrates and invertebrates, including insects. We have determined the complete nucleotide sequence of the gypsy moth VgmRNA, which shows that its structure is significantly different from VgmRNAs in other systems. The nucleotide sequence was determined using overlapping cDNA fragments generated from RACE reactions and rTh polymerase-mediated PCR. The VgmRNA is 5579 nucleotides long and codes for both the large and small subunits. However, the arrangement of the subunit encoding regions in the gypsy moth VgmRNA is opposite of what has been observed in other systems. Gypsy moth Vg gene is the first reported example of a Vg gene where the 5'-terminal region codes for the large subunit and the 3'-terminal region for the small subunit. Also, the sequence near the junction of subunits was significantly different from those found in other insects. This may be responsible for the relatively more stable precursor of Vg subunits found in the gypsy moth hemolymph. It is not clear where this divergence in the structure of Vg gene occurred during evolution, since the Vg gene of another lepidopteran, Bombyx mori, conforms to the structure of those in vertebrates and other invertebrates.

Amino Acid Sequence↗
PubMed1994

Influence of handedness on the visual and auditory reaction time.

Visual Reaction Time (VRT) and Auditory Reaction Time (ART) were measured in right-handed and left-handed human volunteers, using an Electronic Response Timer Unit. The study demonstrated that a group of left-handed women reacted faster (P < 0.05) with their left hand to an auditory stimulus than their counterpart using their right hand. VRT did not show any significant change within, and between, the groups and was not influenced by sex or age. The observed differences in ART may be due to central phenomenon.

Adolescent↗
PubMed1990

Molecular cloning, regulation, and complete sequence of a hemocyanin-related, juvenile hormone-suppressible protein from insect hemolymph.

A cDNA library was prepared from mRNA isolated from the lepidopteran Trichoplusia ni during larval-pupal metamorphosis. Differential probing was used to identify clones for mRNAs which are suppressible by exogenous juvenile hormone treatment. In vitro transcribed cRNAs from these clones were translated in vitro and challenged with antiserum specific for a known acidic, juvenile hormone-suppressible hemolymph protein (AJSP-1) that is associated with larval metamorphosis. Three clones were found which encoded immunoreactive translation products; their identity was confirmed by comparison of the N-terminal sequence of the mature AJSP-1 protein with the cDNA sequence. As inferred from the cDNA sequence, the protein encompasses 704 amino acid residues, including a N-terminal signal peptide; widely distributed as well as more localized stronger sequence similarities indicate that the protein is distantly related to hemocyanins and hemocyanin-like insect proteins. However, on the basis of amino acid sequence and composition, immunological reactivity, and hormonal sensitivity, the protein is distinct from previously described insect proteins. Its juvenile hormone suppressibility can be ascribed to suppression of the mRNA. RNA blot analysis using the cloned cDNA as a probe demonstrated that the transcript (approximately 2.8 kilobases) is of very low abundance during the penultimate stadium but becomes very abundant during the last larval stadium, when juvenile hormone rapidly declines. Furthermore, treatment of larvae with a juvenile hormone analog strongly suppresses the abundance of the message.

Amino Acid Sequence↗
PubMed1987

Biochemical and immunological properties of different electrophoretic forms of juvenile hormone esterase from Trichoplusia ni (Hübner).

The two major electrophoretic forms (pI 5.5, 5.3) of juvenile hormone esterase were independently isolated from hemolymph of larval Trichoplusia ni. A simple and rapid preparation procedure of poly(ethylene glycol) precipitation, Sephadex gel filtration and chromatofocusing is described. Analytical isoelectric focusing showed only one peak of juvenile hormone esterase activity in the respective purified samples, whereas there were four (two major) such peaks in the hemolymph. The amino acid composition of the two forms was similar. The comparison of peptides obtained after protein fragmentation by cyanogen bromide showed that juvenile hormone esterases A and B were very similar, although definitely not identical, in amino acid sequence. The immunological comparisons of juvenile hormone esterases suggested that the number of polyclonal antibody binding sites on both forms was the same. There were no detected differences between immunoreactive properties of juvenile hormone esterase from the hemolymph of different stages of larval maturation. The influence of the active site of the enzyme on its antigenic properties was studied by immunocompetition. The inactive, heat-denatured juvenile hormone esterase can only partially protect against inhibition of its activity by the antibodies, whereas an organophosphate inhibitor which covalently binds to the catalytic center of the enzyme did not change the immunoreactive properties in comparison to active juvenile hormone esterase from hemolymph. These data show that heat-denatured juvenile hormone esterase has lost at least one or more epitopes, but the catalytic site of the enzyme is distinct from the epitopes.

Amino Acids↗
PubMed1986

Terminal structure of hypovirulence-associated dsRNAs in the chestnut blight fungus Endothia parasitica.

The 3'- and 5'-terminal sequences of the five large double-stranded RNA species (L-dsRNA; 4.5-6.0 X 10(6) daltons) of EP713, a hypovirulent strain of Endothia parasitica, were determined by mobility-shift and enzymatic methods. All the L-dsRNAs appeared to have identical terminal sequences. A heteropolymer sequence was found at one 3'-terminus and a poly(A) sequence of variable length at the other. It was possible to label only one 5'-terminus using polynucleotide kinase and [gamma-32P]ATP, and this was shown to be a poly(U) sequence of variable length. We propose that the dsRNAs have the following structure, where X represents a blocking group: (Formula: see text). A recombinant plasmid containing dsRNA-related sequences was constructed. Hybridization analysis using the recombinant probe indicated that the sequence homology among the L-dsRNAs extended beyond these terminal regions and was also shared by small dsRNAs (0.3-0.45 X 10(6) daltons).

Ascomycota↗
PubMedDate not supplied

Does left ventricular function improve with L-carnitine after acute myocardial infarction?

A double blind randomized placebo controlled clinical trial was carried out to assess the efficacy and safety of L-carnitine in patients suffering from acute anterior wall myocardial infarction with respect to left ventricular function. Sixty patients (34 men, 26 women, mean age 56+11 yr.) with acute anterior wall myocardial infarction were randomized to placebo and L-carnitine. All the patients were given intravenous L-carnitine / placebo in the dose of 6gm/day for the first seven days followed by oral L-carnitine / placebo 3 gm/day in three divided doses for a period of three months. Echocardiography was performed for regional wall motion abnormality, left ventricular end systolic volume (ESV), end diastolic volume (EDV) and ejection fraction (EF) on admission, after seven days and after three months of the infarction. Forty-four patients completed the study. There were three deaths, two in the placebo and one in the L-carnitine group (p>0.05). Thirteen patients were lost to follow up. Echo parameters in both groups were comparable (p>0.05). The duration of chest pain prior to initiation of the I.V. L-carnitine was 7.5 + 5.2 hrs in the L-carnitine group and 7 + 4 hrs in the placebo group (p>0.05). There was no statistical difference in the EF, ESV and EDV on admission, at discharge and after three months in the L-carnitine and the placebo groups (p>0.05). No significant adverse effects were noted. L-carnitine, though a safe drug, does not affect the left ventricular function in patients with myocardial infarction.

Aged↗