Disease relevance of CL-43

• Conglutinin and CL-43 show antiviral activities towards influenza A virus and rotaviruses [1].
• 8. The CL-43 promoter has 96% identity with the conglutinin promoter recently described by us, and the assignment of potential cis-regulatory elements shows that several hepatic transcription factors may regulate transcription in the acute phase response and in response to metabolic changes [2].
• We have isolated a genomic conglutinin phage clone and found that the 5'-flanking region shows 95.8% identity with the sequence previously published, which on the other hand shows 99.7% identity with the CL-43 promoter [3].

High impact information on CL-43

• However, CL-43, a bovine serum lectin, which evolved through duplication of the surfactant protein D gene in ruminants, prefers mannose and mannose-rich polysaccharides [4].
• Insertion of the CL-43 RAK sequence or a control Ala-Ala-Ala sequence (AAA) into the corresponding position in NCRD increased the efficiency of binding to mannan and changed the inhibitory potencies of competing saccharides to more closely resemble those of CL-43 [4].
• An inhibition assay with biotinylated CL-43, using solid-phase mannan as ligand, revealed the following carbohydrate inhibition pattern: mannose and ManNAc > fucose > GlcNAc > glucose and maltose > galactose > lactose >> GalNAc [5].
• Like SP-D, CL-43 also strongly enhanced neutrophil uptake of IAV [6].
• Like natural CL-43, the recombinant is secreted as trimeric forms that show a preference for mannose and N-acetyl mannosamine [6].

Biological context of CL-43

• The genes encoding conglutinin, CL-43 and CL-46 are located on the bovine chromosome 28, and phylogenetic analysis indicates their common origin--from the lung surfactant protein D gene [1].
• We have studied molecular and genomic characteristics of CL-43 to identify polymorphisms that might be associated with disease-susceptible phenotypes or other traits in cattle, and to elucidate how the Bovidae may benefit from possessing additional collectins [2].
• Screening a bovine cDNA library resulted in the isolation of two plasmid clones that encoded the entire translated sequence of CL-43 [2].
• CL-43 is a serum collectin involved in the innate immunity of cattle and variability of serum CL-43 may relate to disease in cows [7].
• No circadian rhythm (24-h variation) in CL-43 plasma levels was observed, indicating that plasma levels were not influenced by e.g. feeding [7].

Anatomical context of CL-43

• Northern blot or immunocytochemical analysis confirm biosynthesis of bovine collectins mainly in the liver (conglutinin, CL-43) and in the thymus (CL-46) [1].

Associations of CL-43 with chemical compounds

• CL-43 was sandwiched between the capture antibodies and the monoclonal antibody and the detection was optimised with biotin-labelled secondary antibodies and streptavidin-Eu3+ [7].
• We have investigated the binding specificity of CL-43 using as model systems a panel of structurally defined oligosaccharides in the form of neoglycolipids, and several glycoproteins derived from the complement glycoprotein C3 during activation of the complement cascade [8].
• These are features shared with other serum collectins, conglutinin and mannan-binding proteins; a major difference is the lack of detectable binding by CL-43 to N-glycosidic oligosaccharides terminating in N-acetylglucosamine [8].
• When these glycoproteins are sodium dodecyl sulphate (SDS)-treated and immobilized on nitrocellulose, CL-43 (but not conglutinin nor mannan-binding protein) binds strongly to C3(H2O), iC3b and C3c [8].

Other interactions of CL-43

• Conglutinin, CL-43 and CL-46--three bovine collectins [1].
• CL-43, lung surfactant protein D (SP-D) and conglutinin showed no complement-activating properties under the same conditions [9].

Analytical, diagnostic and therapeutic context of CL-43

• For CL-43, sequence alignments demonstrate a basic insertion, Arg-Ala-Lys (RAK), immediately N-terminal to the first motif [4].
• Two-dimensional gel electrophoresis showed that CL-43 has two isoforms, with pI values of 4.9 and 5.3, corresponding to the native form and the truncated form of the molecule respectively [9].
• CL-43 was purified by affinity chromatography on mannan-Sepharose [9].
• A previously undescribed bovine serum lectin (designated CL-43) was identified by its Ca(2+)-dependent binding to mannan and by its molecular mass of 43 kDa under reducing conditions on SDS-PAGE [5].
• Electron microscopy of purified CL-43 revealed only rod-like monomer subunits 37.4 nm long [10].

References