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F Hamel

Publications and source records attributed to F Hamel.

9 recordsLinked to original sources
PubMed2003

Mapping of the bovine herpesvirus 1 glycoprotein C promoter region and its specific transactivation by the viral BICP27 gene product.

We investigated the cis-acting sequences of the promoter regulating the gene encoding the glycoprotein C (gC) of bovine herpesvirus 1 (BoHV-1), a gene of the gamma1 class. S1 nuclease protection assays revealed that gC transcription initiated predominantly at position C18281 of the viral genome, corresponding to 21 and 56 bases downstream from putative TATA-like and CAAT boxes, respectively. To map the gC promoter (pgC), we measured the ability of a series of nested deletions of the region +71 to -1155 with respect to the major gC transcriptional start site, to drive expression of the firefly luciferase (Luc) reporter gene following transient transfection of a cell host, in the absence as well as in the presence of viral factors expressed in trans. We show that the minimal pgC sequences required to drive maximal BoHV-1 independent expression was within the region +71 to -76 which harbours the putative TATA and CAAT boxes, the mRNA start site, and the complete 5' transcript leader sequence. This small pgC fragment was highly trans-activated by the co-expression of the BoHV-1-encoded BICP27 protein, but not BICP0 nor BTIF. In contrast, the pgC fragment spanning the region +71 to -1155 was only minimally trans-activated by BICP27, but substantially stimulated by BICP0. These findings thus suggest that gC gene regulation may involve the combined action of several viral transactivators.

Animals↗
PubMed1998

Isolation and characterization of wheat aluminum-regulated genes: possible involvement of aluminum as a pathogenesis response elicitor.

Using differential screening of a root tip cDNA library prepared from an Al-tolerant wheat cultivar (Triticum aestivum L. cv. Atlas-66) exposed to Al, we have isolated and characterized several wheat aluminum-regulated (War) cDNAs. Sequence comparison revealed that genes up-regulated by Al correspond to peroxidase (war4.2), cysteine proteinase (war5.2), phenylalanine-ammonia lyase (war7.2), and oxalate oxidase (war13.2). Two wheat cultivars that differ in their level of tolerance (cv. Atlas-66: tolerant, and cv. Fredrick: sensitive) were used to evaluate the relationship between the accumulation of War mRNAs and Al toxicity, as measured by root growth inhibition (RGI). The mRNA accumulation was modulated to similar levels in both cultivars compared at equivalent RGIs. This indicates that War mRNA accumulation is associated with the toxicity of Al rather than with the cultivar's tolerance. It appears that most of the genes found to be up-regulated by Al share homologies with genes induced by pathogens. This suggests that Al may act as an elicitor of a pathogenesis-related transduction pathway. The potential functions of the up-regulated war genes in cell wall strengthening and Al trapping are discussed.

Aluminum↗
PubMed1997

Structural and evolutionary relationships among chitinases of flowering plants.

The analysis of nuclear-encoded chitinase sequences from various angiosperms has allowed the categorization of the chitinases into discrete classes. Nucleotide sequences of their catalytic domains were compared in this study to investigate the evolutionary relationships between chitinase classes. The functionally distinct class III chitinases appear to be more closely related to fungal enzymes involved in morphogenesis than to other plant chitinases. The ordering of other plant chitinases into additional classes mainly relied on the presence of auxiliary domains-namely, a chitin-binding domain and a carboxy-terminal extension-flanking the main catalytic domain. The results of our phylogenetic analyses showed that classes I and IV form discrete and well-supported monophyletic groups derived from a common ancestral sequence that predates the divergence of dicots and monocots. In contrast, other sequences included in classes I* and II, lacking one or both types of auxiliary domains, were nested within class I sequences, indicating that they have a polyphyletic origin. According to phylogenetic analyses and the calculation of evolutionary rates, these chitinases probably arose from different class I lineages by relatively recent deletion events. The occurrence of such evolutionary trends in cultivated plants and their potential involvement in host-pathogen interactions are discussed.

Amino Acid Sequence↗
PubMed1995

Characterization of a class I chitinase gene and of wound-inducible, root and flower-specific chitinase expression in Brassica napus.

Complementary and genomic DNAs coding for a Brassica napus chitinase have been cloned and sequenced. The genomic DNA contains one intron and encodes a 322-amino acid basic chitinase with a 20-amino acid N-terminal signal peptide followed by a 40-amino acid cysteine-rich domain, linked by a hinge region to the main domain of the enzyme. The sequence of the cDNAs is identical to the exon sequence deduced from the genomic DNA. A probe derived from this gene identified a 1.2-kb transcript present in high amount in roots, moderate in floral tissues and low in stems and leaves. The synthesis of these transcripts is regulated during development and is induced in roots by wounding and ethephon. This type of chitinase is encoded by two sequences in Brassica napus, as shown either by Southern hybridizations or by genomic amplification and sequencing using the polymerase chain reaction. These genes are homologous to one sequence found in the Brassica oleracea genome.

Amino Acid Sequence↗
PubMed1994

Stage-specific transcription of the homebox gene Bnhd1 in young tissues and flowers of Brassica napus.

The Bnhd1 cDNA, only distantly related to published homebox gene sequences, was isolated from Brassica napus by the polymerase chain reaction. The Bnhd1 transcript was detected in all organs of young seedlings, but only in the youngest leaves and flowers of mature plants. A 4- and 7-fold increase in transcription levels was observed after wounding of young roots and leaves, respectively.

Amino Acid Sequence↗
PubMed1991

Cleavage of vasoactive intestinal peptide at multiple sites by autoantibodies.

Vasoactive intestinal peptide (VIP) fragments generated by autoantibodies purified from the blood of two human beings were separated and sequenced. Based on the identity of these fragments, seven peptide bonds cleaved by the antibodies were identified. Six of the seven scissile bonds are clustered in the region of VIP spanning residues 14-22 and were cleaved by antibodies from both human subjects. The seventh scissile bond is located at residues 7-8 and was cleaved by antibodies from one of the subjects. The scissile bonds link amino acid residues with different size, charge, and hydrophobicity. The hydrolytic activity of the antibodies was selective in that they failed to hydrolyze polypeptides unrelated in sequence to VIP (insulin and atrial natriuretic peptide). These observations demonstrate substrate specific hydrolysis by naturally occurring antibodies and expand the range of peptide bonds hydrolyzed by these antibodies.

Amino Acid Sequence↗
PubMedDate not supplied

Physical therapy competencies: a market study.

As an initial step toward curricula reevaluation and change, this study was designed to develop a list of competencies, applicable for entry-level physical therapists and appropriate to the present-day rehabilitation needs in the province of Québec. A comprehensive set of competence statements or items concerning physical therapy practice was compiled. These were subsequently edited, field tested and, through the mechanism of a questionnaire, sent to practising physical therapists in Québec for verification and rating. The level-of-importance ratings in professional practice of the 224 competence statements or items (which had been grouped into 11 categories encompassing ethics, evaluation, treatment skills, research, professional growth, administrative skills and theoretical knowledge) gave indications as to their applicability in the work market. The ratings of importance of each category were further analyzed in relation to the respondent's years of professional practice, place of training, type of position held, and work setting. Only for the variables years of experience and place of training were there any significant differences in importance ratings. The response ratings given to the competence statements and the categories can result in the determining of possible directions for educational curricula changes that would meet market demands, both at the undergraduate and graduate levels as well as in the area of continuing education programs.

Analysis of Variance↗