Efficient association of an amino-terminally extended form of human latent transforming growth factor-beta binding protein with the extracellular matrix.
Latent transforming growth factor-beta (TGF-beta) binding protein-1 (LTBP-1) is a component of the high molecular weight latent TGF-beta complex found in various cells, including human platelets. LTBP-1 is observed as different molecular sizes in different cell types, probably due to proteolytic processing and alternative splicing. We here report a novel form of human LTBP-1, which is longer in its NH2-terminal part (LTBP-1L). Northern hybridization analysis revealed that the LTBP-1L is derived from a 7.0-kilobase mRNA, whereas the originally reported shorter form (LTBP-1S) is derived from a 5.2-kilobase mRNA. Transfection of cDNA for LTBP-1L and -1S in COS cells revealed that LTBP-1L bound more efficiently to the extracellular matrix than did LTBP-1S. These results suggest that the different splice forms of LTBP-1 mediate different localization patterns of the latent TGF-beta complexes in vivo.
Ludwig Institute for Cancer Research, Biomedical Center, Uppsala, Sweden.
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A
Olofsson
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Ichijo
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Morén
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ten Dijke
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Miyazono
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Heldin
D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary; D005109:Extracellular Matrix / Q000378:metabolism*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D053779:Latent TGF-beta Binding Proteins; D008969:Molecular Sequence Data; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017386:Sequence Homology, Amino Acid; D016212:Transforming Growth Factor beta / Q000378:metabolism*
D002352:Carrier Proteins; D018076:DNA, Complementary; D047908:Intracellular Signaling Peptides and Proteins; C509032:LTBP1 protein, human; D053779:Latent TGF-beta Binding Proteins; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta