Disease relevance of hsdM

• Sequences of the hsdM gene, encoding one of the three subunits of type I restriction-modification systems, have been determined for four strains of enterobacteria [1].
• The Sau1 type I restriction-modification system is found on the chromosome of all nine sequenced strains of Staphylococcus aureus and includes a single hsdR (restriction) gene and two copies of hsdM (modification) and hsdS (sequence specificity) genes [2].
• Since the phage of the SK and hsp II phenotypes is effectively restricted in respective cells it may be assumed that the isomethymeric modification does not provide any protection against the corresponding restrictases [3].
• A DNA region of Clostridium acetobutylicum containing a gene (hsp 18) with significant homology to a family of small eukaryotic heat shock proteins was cloned and sequenced [4].
• The murine hsp 70.2 gene, encoding P70, was cloned and expressed in Escherichia coli [5].

High impact information on hsdM

• The efficiency of the copia LTRs varies considerably between the cell lines we tested, whereas that of the hsp 70 promoter does not [6].
• The GII methylase recognizes the five-member symmetric sequence: 5'...NpCpCpApGpGpN...3'. This sequence is identical with the recognition site of the hsp II type determined by RII plasmid but, in contrast to RII methylase, the GII enzyme methylates cytosine located on the 5' side of the site [3].
• A total of 7.2 kb DNA sequencing data revealed three open reading frames, corresponding to hsdR, hsdM and hsdS genes of type I R-M systems [7].
• Mutants with enhanced spontaneous mutability (hsm) to canavanine resistance were induced by N-methyl-N-nitrosourea in Saccharomyces cerevisiae [8].
• The activator locus, alxA, is part of a continuous open reading frame that includes the type I hsdM methylase gene [9].

Biological context of hsdM

• These proteins are critical to cell survival, and those of the 70,000 MW group (hsp 70) are essential for cell division and proliferation [10].
• These observations suggest that bleomycin exposure may cause significant alterations in important DNA promoter regions such as the hsp 70 promoter and point to new ways to assess bleomycin-induced changes in cells [10].
• To evaluate the effect of bleomycin on heat shock gene expression, we transfected a gene construct containing the hsp 70 heat shock gene promoter into fibroblasts [10].
• Thus, in contrast to hsp 65 itself, recognition of epitope 180-188 in the context of PhoE appeared to be independent of antigen-processing events [11].
• Yet another family of stress proteins, the hsp 60 or GroEL proteins (chaperonins), appear to function as catalysts of protein folding [12].

Anatomical context of hsdM

• At the level of polyclonal T cell responses the epitope in the context of PhoE is recognized more efficiently than 180-188 as synthetic peptide or in the context of the hsp 65 molecule itself [11].
• Doses of bleomycin, which have previously been shown to augment lung fibroblast proliferation, induce the hsp 70 heat shock promoter in the transfected cells [10].
• Bleomycin induces the hsp 70 heat shock promoter in cultured cells [10].
• A member of one of these families, hsp 60, has been shown to play a global role in polypeptide chain folding in mitochondria [13].
• Mitochondrial hsp 70 has a distinct role in driving translocation across outer and inner mitochondrial membranes and probably in supporting unfolding of precursors in the cytosol [14].

Associations of hsdM with chemical compounds

• Thus, the serine and threonine residues of the hsp 150 delta-NGFRe fusion protein were highly selectively O-glycosylated [15].
• The hsp 150 delta-carrier has 95 serine and threonine residues, which were extensively O-glycosylated [15].

Analytical, diagnostic and therapeutic context of hsdM

• PCR amplification from mRNA, however, yielded only the sequence expected for the expressed hsp 60 protein [16].
• Parallel to the effects displayed by immunisation with hsp, oral administration of hsp-containing OM-89 was found to modify autoimmune disease in a number of animal models, such as for arthritis, diabetes and SLE [17].

References