Disease relevance of CA8

• Overexpression of carbonic anhydrase-related protein XI promotes proliferation and invasion of gastrointestinal stromal tumors [1].
• Expression of carbonic anhydrase-related protein CA-RP VIII in non-small cell lung cancer [2].
• A murine carbonic anhydrase-related protein (CARP) has been expressed in Escherichia coli and purified to near homogeneity [3].
• Relation between Carp (multiple-sclerosis associated) agent and multiple sclerosis [4].
• It is suggested that the Carp (multiple-sclerosis associated and scrapie associated) agents may be the V-R.N.A. form of slow (D.N.A.) viruses which are the aetiological agents of the two diseases [4].

High impact information on CA8

• In six healthy subjects, similar caloric loads (117 cals) of oleic acid, essential amino acids, and glucose in isomolar (280 mosmol/L), similar pH (7.4) solutions were infused into the right colon at 10 ml/min through a colonic tube passed by mouth [5].
• CA8 encodes carbonic anhydrase-related protein (CARP) VIII, preferentially expressed in Purkinje cells [6].
• Carbonic anhydrase-related protein VIII: autoantigen in paraneoplastic cerebellar degeneration [6].
• In this study, we comparatively analyzed expression of Arpp and Carp protein in skeletal and cardiac muscles and rhabdomyosarcomas (RMSs) [7].
• In adult skeletal muscle, Arpp was preferentially expressed in the nucleus and cytoplasm of type I fibers, whereas Carp was barely detectable in skeletal muscle [7].

Chemical compound and disease context of CA8

• Arpp, a protein containing an ankyrin repeat domain, PEST sequence, and proline-rich region, is a novel ankyrin-repeated protein highly homologous to Carp, which is proposed to be the putative genetic marker for cardiac hypertrophy [7].

Biological context of CA8

• Sequence and tissue expression of a novel human carbonic anhydrase-related protein, CARP-2, mapping to chromosome 19q13.3 [8].
• Four substitutions of key amino acids in the catalytic domain of CAs (equivalent to His94Arg, His96Leu, His119Gln, and Thr199Ser) are likely to render CARP-2 inactive as a carbonic anhydrase [8].
• The deduced amino acid sequence of human carbonic anhydrase-related protein (CARP) is 98% identical to the mouse homologue [9].
• Expression of the acatalytic carbonic anhydrase VIII gene, Car8, during mouse embryonic development [10].
• Two point mutations convert a catalytically inactive carbonic anhydrase-related protein (CARP) to an active enzyme [3].

Anatomical context of CA8

• A recently reported mRNA, encoding 'carbonic anhydrase-related polypeptide' (CARP) from the Purkinje cells of mouse cerebellum, was shown to have a 30-40% deduced amino acid sequence identity with the carbonic anhydrases (CA) of mammals [9].
• On the other hand, in adult cardiac muscle, interestingly, Arpp was expressed in ventricles mostly, whereas Carp was expressed throughout the atrium and ventricle [7].
• Since ATP is the major organic phosphate in the erythrocytes of many fish, the binding of ATP to a representative fish hemoglobin (Carp I) was investigated [11].
• Furthermore, although Carp was identified in fetal heart at 11 developmental weeks, Arpp was very low or undetectable in these fetal hearts [7].
• Less than 5% of epithelial cells in normal colonic mucosae (n = 73) were CA-RP VIII-positive and these were localized to the deep part of the cryptal epithelium [12].

Associations of CA8 with chemical compounds

• A single mutation, involving the replacement of an arginine residue with histidine to reconstruct a zinc-binding site, suffices to change a catalytically inactive murine carbonic anhydrase-related protein (CARP) to an active carbonic anhydrase with a CO2-hydration turnover number of 1.2 x 104 s-1 [13].

Other interactions of CA8

• cDNA sequence of human carbonic anhydrase-related protein, CA-RP X: mRNA expressions of CA-RP X and XI in human brain [14].
• A full-length cDNA clone of a human carbonic anhydrase-related protein, CA-RP XI encoded by CA11, was obtained and sequenced [15].
• For immunohistochemical reaction a monoclonal antibody specific for parvalbumin II component of the Carp muscles (Pv Carp II) was used [16].
• Gerbils were maintained either at thermoneutrality (TN) or cold [4 degrees C, ambient temperature (Ta)] for 4 (CA4) or 8 (CA8) wk [17].
• To investigate a potential role for CA-RP VIII in human colorectal epithelial carcinogenesis, colorectal tissue specimens from surgically resected adenocarcinomas (n = 60) and endoscopically polypectomized adenomas (n = 13) were analysed by immunohistochemistry using monoclonal antibodies to CA-RP VIII and Ki-67 antigen [12].

Analytical, diagnostic and therapeutic context of CA8

• The human carbonic anhydrase (CA) VIII gene (CA8) has been mapped to chromosome 8 at q11-->q12 by human-mouse hybrid mapping and by fluorescence in situ hybridization [18].
• Furthermore, we found that mArpp- and Carp-expression in skeletal muscle were markedly up-regulated after denervation [19].
• Protein sequence analysis revealed that Arpp is homologous (52.7% identity) to Carp which is shown to be involved in the regulation of the transcription of the cardiac ventricular myosin light chain 2 gene [20].
• 3. Its molecular weight, as determined by gel filtration technique, is 131,800 daltons and the energy of activation for this enzyme is 15,205 cals/mole [21].

References