Alternative titles; symbols
HGNC Approved Gene Symbol: CLTB
Cytogenetic location: 5q35.2 Genomic coordinates (GRCh38): 5:176,392,455-176,416,569 (from NCBI)
Clathrin is the main structural component of the lattice covering the cytoplasmic face of the coated pits and coated vesicles in which specific macromolecules are entrapped in the process of receptor-mediated endocytosis. Clathrin is a large, soluble protein composed of heavy chains, which have molecular masses of about 192 kD, and light chains, which have molecular masses of about 32 to 38 kD. Two major classes of clathrin light chains, referred to as LCA (CLTA; 118960) and LCB (CTLB), have been identified (summary by Kirchhausen et al., 1987). For additional information on clathrin, see 118960.
Jackson et al. (1987) identified 4 distinct forms of bovine clathrin light chains. This molecular variability derived from tissue-specific splicing of Lca and Lcb genes.
Brodsky et al. (1987) identified that part of the light chain sequence that mediates heavy chain binding and is the region of strongest homology with intermediate filament proteins. Sequence analysis shows an overall homology of 60% between LCA and LCB and the presence of brain-specific insertion sequences.
Jackson and Parham (1988) compared cDNAs encoding the brain and nonbrain forms of human LCA and LCB with their homologs in cow and rat. The significant differences that distinguish LCA from LCB and the brain from the nonbrain forms show remarkable preservation in all 3 species. Each clathrin triskelion consists of 3 heavy chains and 3 light chains. In the brain, tissue-specific mRNA splicing yields larger forms of LCA and LCB, containing additional insertion sequences of 30 and 18 amino acids, respectively.
By Southern blot analysis carried out on genomic DNA extracted from a panel of mouse-human somatic cell hybrids and by isotopic in situ hybridization, Ponnambalam et al. (1994) assigned the CLTB gene to human chromosome 4q2-q3. However, Gross (2011) mapped the CLTB gene to chromosome 5q35.2 based on an alignment of the CLTB sequence (GenBank BC006457) with the genomic sequence (GRCh37).
Brodsky, F. M., Galloway, C. J., Blank, G. S., Jackson, A. P., Seow, H.-F., Drickamer, K., Parham, P. Localization of clathrin light-chain sequences mediating heavy-chain binding and coated vesicle diversity. Nature 326: 203-205, 1987. [PubMed: 2434865] [Full Text: https://doi.org/10.1038/326203a0]
Gross, M. B. Personal Communication. Baltimore, Md. 4/20/2011.
Jackson, A. P., Parham, P. Structure of human clathrin light chains: conservation of light chain polymorphism in three mammalian species. J. Biol. Chem. 263: 16688-16695, 1988. [PubMed: 3267234]
Jackson, A. P., Seow, H.-F., Holmes, N., Drickamer, K., Parham, P. Clathrin light chains contain brain-specific insertion sequences and a region of homology with intermediate filaments. Nature 326: 154-159, 1987. [PubMed: 3821891] [Full Text: https://doi.org/10.1038/326154a0]
Kirchhausen, T., Scarmato, P., Harrison, S. C., Monroe, J. J., Chow, E. P., Mattaliano, R. J., Ramachandran, K. L., Smart, J. E., Ahn, A. H., Brosius, J. Clathrin light chains LCA and LCB are similar, polymorphic, and share repeated heptad motifs. Science 236: 320-324, 1987. [PubMed: 3563513] [Full Text: https://doi.org/10.1126/science.3563513]
Ponnambalam, S., Jackson, A. P., LeBeau, M. M., Pravtcheva, D., Ruddle, F. H., Alibert, C., Parham, P. Chromosomal location and some structural features of human clathrin light-chain genes (CLTA and CLTB). Genomics 24: 440-444, 1994. [PubMed: 7713494] [Full Text: https://doi.org/10.1006/geno.1994.1650]