Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.6 (RNA polymerase)
 34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cathelicidins are the precursors of potent antimicrobial peptides that have been identified in several mammalian species. Prior work has suggested that members of this gene family can participate in host defense through their antimicrobial effects and activate mesenchymal cells during wound repair. To permit further study of these proteins a reverse transcriptase-polymerase chain reaction approach was used to identify potential mouse homologs. A full-length 562-base pair cDNA clone was obtained encoding an NH2-terminal prepro domain homologous to other cathelicidins and a unique COOH-terminal peptide. This gene, named Cramp for cathelin-related antimicrobial peptide, was mapped to chromosome 9 at a region of conserved synteny to which genes for cathelicidins have been mapped in pig and man. Northern blot analysis detected a 1-kilobase transcript that was expressed in adult bone marrow and during embryogenesis as early as E12, the earliest stage of blood development. Reverse transcriptase-polymerase chain reaction also detected CRAMP expression in adult testis, spleen, stomach, and intestine but not in brain, liver, heart, or skeletal muscle. To evaluate further the expression and function of CRAMP, a peptide corresponding to the predicted COOH-terminal region was synthesized. CD spectral analysis showed that CRAMP will form an amphipathic alpha-helix similar to other antimicrobial peptides. Functional studies showed CRAMP to be a potent antibiotic against Gram-negative bacteria by inhibiting growth of a variety of bacterial strains (minimum inhibitory concentrations 0.5-8.0 microM) and by permeabilizing the inner membrane of Escherichia coli directly at 1 microM. Antiserum against CRAMP revealed abundant expression in myeloid precursors and neutrophils. Thus, CRAMP represents the first antibiotic peptide found in cells of myeloid lineage in the mouse. These data suggest that inflammatory cells in the mouse can use a nonoxidative mechanism for microbial killing and permit use of the mouse to study the role such peptides play in host defense and wound repair.
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PMID:Identification of CRAMP, a cathelin-related antimicrobial peptide expressed in the embryonic and adult mouse. 914 21

A database search identified a rat cDNA clone which phylogenetic analysis revealed to encode a cathelicidin most similar to mouse cathelicidin CRAMP. The analysis also showed that the evolutionary pattern of the cathelicidin family is lineage specific. The rat cathelicidin is called rCRAMP. Its peptide was isolated from granulocytes, and determined to be 43 amino acids long by mass spectrometry and N-terminal sequencing. Synthetic rCRAMP had antimicrobial activity. The expression of rCRAMP was investigated by reverse-transcriptase polymerase chain reaction followed by Southern hybridization and by Western blot analysis. rCRAMP was identified in granulocytes, thymus, testis, lung, mouth mucosa, tongue, oesophagus, colon, caecum and small intestine, a distribution similar to cathelicidins of mouse and human. The rat is a small laboratory animal with additional disease models available compared to the mouse. Our results open up the possibility to use the rat as a model system to study responses connected to cathelicidin expression in health and disease.
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PMID:Phylogeny, processing and expression of the rat cathelicidin rCRAMP: a model for innate antimicrobial peptides. 1273 13