title: Molecular cloning of the mouse Ltbp-1 gene reveals tissue specific expression of alternatively spliced forms.
abstract: Latent transforming growth factor binding proteins (Ltbp-1, -2, -3 and -4) and fibrillins (Fbn-1 and -2) are structurally related cysteine-rich extracellular matrix proteins that localize to the 10 nm microfibrils. Ltbp-1 is thought to promote the secretion and proper folding of the small latent transforming growth factor beta (TGF-beta) complex (TGF-beta plus its propeptide) and is implicated in sequestering it in the extracellular matrix. Here we report the isolation of the mouse Ltbp-1 complementary DNA (cDNA) and gene. The longer form of the Ltbp-1 cDNA encodes a predicted 1713 amino acid protein containing 18 epidermal growth factor-like repeats, four 8-cysteine domains and several motifs that suggest interactions with alpha(IV)beta(1) and alpha(9)beta(1) integrins. Northern blotting analyses indicate that long and short Ltbp-1 transcripts are widely expressed in adult mouse tissues and most abundantly expressed in heart. Ltbp-1 is a single copy gene that maps to chromosome 17, band E (1-3) and encompasses more than 212 kb. The Ltbp-1 gene contains 34 exons and shows a similar organization to the LTBP-2 gene, suggesting that these genes originated from a common ancestral gene.
authors.affiliation: Department of Cell Biology, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA.
authors.forename: Irene
authors.initials: I
authors.lastname: Noguera
authors.forename: Hiroto
authors.initials: H
authors.lastname: Obata
authors.forename: Anna
authors.initials: A
authors.lastname: Gualandris
authors.forename: Pamela
authors.initials: P
authors.lastname: Cowin
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Rifkin
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002352:Carrier Proteins / Q000235:genetics*; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D005091:Exons; D015870:Gene Expression; D005796:Genes / Q000235:genetics; D017404:In Situ Hybridization, Fluorescence; D047908:Intracellular Signaling Peptides and Proteins; D007438:Introns; D053779:Latent TGF-beta Binding Proteins; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA
chemical_list: D002352:Carrier Proteins; D018076:DNA, Complementary; D047908:Intracellular Signaling Peptides and Proteins; D053779:Latent TGF-beta Binding Proteins; C509033:Ltbp1 protein, mouse; C509036:Ltbp2 protein, mouse; D020033:Protein Isoforms; D012333:RNA, Messenger; D004247:DNA