title: Structure of the human laminin gamma 2 chain gene (LAMC2): alternative splicing with different tissue distribution of two transcripts.
abstract: We have determined the structure of the human laminin gamma 2 chain gene (LAMC2), which is mutated in some patients with junctional epidermolysis bullosa. Eight lambda phage clones isolated from a genomic library and three subgenomic lambda phage clones made from a plasmid artificial chromosome clone spanned 75 kb, including the 55-kb gene. The LAMC2 gene contains 23 exons and is structurally highly homologous with the 28-exon LAMC1 gene (Kallunki et al., 1991, J. Biol. Chem. 266: 221-228), with 16 exons having identical sizes in the two genes. The gene analysis demonstrated that two previously described different size gamma 2 chain cDNAs (Kallunki et al., 1992, J. Cell Biol. 119: 679-693) are the result of alternative splicing. The longer gamma 2 chain is formed by using the coding sequence of the last exon 23, while the shorter gamma 2* chain is formed by using only 22 exons, together with part of the 5' end of intron 22. The two mRNAs were shown to have different expression patterns in 17-week-old human embryonic tissues, with the longer gamma 2 chain transcript strongly expressed in epithelia of all tissues studied, while distinct expression of the shorter gamma 2* chain mRNA was observed only in the cerebral cortex, in lung, and in distal tubules of the kidney.
authors.affiliation: Biocenter Oulu, University of Oulu, Finland.
authors.forename: T
authors.initials: T
authors.lastname: Airenne
authors.forename: H
authors.initials: H
authors.lastname: Haakana
authors.forename: K
authors.initials: K
authors.lastname: Sainio
authors.forename: T
authors.initials: T
authors.lastname: Kallunki
authors.forename: P
authors.initials: P
authors.lastname: Kallunki
authors.forename: H
authors.initials: H
authors.lastname: Sariola
authors.forename: K
authors.initials: K
authors.lastname: Tryggvason
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D016109:Epidermolysis Bullosa, Junctional / Q000235:genetics; D005091:Exons; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D017403:In Situ Hybridization; D007231:Infant, Newborn; D007438:Introns; D007797:Laminin / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D011247:Pregnancy; D018075:RNA, Complementary / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014018:Tissue Distribution
chemical_list: D007797:Laminin; D018075:RNA, Complementary; D012333:RNA, Messenger; D004247:DNA