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K Vibe-Pedersen

Publications and source records attributed to K Vibe-Pedersen.

10 recordsLinked to original sources
PubMed1986

Donor and acceptor splice signals within an exon of the human fibronectin gene: a new type of differential splicing.

We have sequenced that area of a human fibronectin gene clone which codes for a connecting strand separating the last two areas of the type III homology. The gene has a complex exon with two 'AG' acceptor sites. One of these can be used (exon subdivision). In addition 93 basepairs inside the exon are sometimes spliced out as an intron. This is the third differential splicing found in the fibronectin gene transcript and it represents a new type of differential splicing.

Base Composition↗
PubMed1985

Location of two of the introns in the antithrombin-III gene.

At least two of the introns in the antithrombin-III (AT-III) gene are located in positions different from those of the other three proteins in this superfamily for which the gene structures are known, namely, ovalbumin, alpha 1-antitrypsin and angiotensinogen. In another part of the 3'-portion of the AT-III gene there is no intron where each of the other three gene structures has one.

Amino Acid Sequence↗
PubMed1985

Primary structure of human fibronectin: differential splicing may generate at least 10 polypeptides from a single gene.

Cellular and plasma fibronectins are heterodimers consisting of similar but not identical polypeptides. The differences between fibronectin subunits are due in part to the variability of internal primary sequences. This results from alternative splicing in at least two regions (ED and IIICS) of the pre-mRNA. The complete primary structure of human fibronectin, including most of the internal variations, has been determined by sequencing a series of overlapping cDNA clones. In total, they covered 7692 nucleotides and represented the mRNA sequence coding from the amino terminus of the mature protein to the poly(A) tail. The deduced amino acid sequence of fibronectin has been analysed in terms of the arrangement of internal homologies and the different binding domains.

Amino Acid Sequence↗
PubMed1984

Human fibronectin: cell specific alternative mRNA splicing generates polypeptide chains differing in the number of internal repeats.

The nucleotide sequence of five independent cDNA clones, which cover 4843 nucleotides from the poly(A) addition site of human fibronectin (FN) mRNA was determined. The deduced amino acid sequence (1383 residues) covers the COOH-terminal 60% of human FN, spanning the C-terminus, fibrin-, heparin- and cell-binding domains, and shows the exact location of the only two free sulphydryl groups present in each subunit chain. We have recently reported two different FN mRNA species; one of them containing an additional 270 nucleotide insert (ED) that encodes exactly one of the homology type III repeats of the protein. The two mRNAs arise by alternative splicing of a common precursor. S1 nuclease mapping of cDNA/RNA hybrids shows that the expression of the two mRNAs is cell specific. Liver only produces the mRNA without the ED, whereas hepatoma cells, breast tumor cells and normal fibroblasts produce both forms of mRNA. Another area of alternative splicing generating three different FN mRNAs in rat liver has been reported by Schwarzbauer et al (16). We here provide evidence for the existence in human cells of a fourth mRNA species different from the three described in rat liver.

Amino Acid Sequence↗
PubMed1984

Human fibronectin: molecular cloning evidence for two mRNA species differing by an internal segment coding for a structural domain.

Two different fibronectin (FN) mRNA species were detected in the human cell line Hs578T. One species, mRNA I, contains an additional 270 nucleotide long insert (ED) that encodes exactly one of the internally repeated structural domains of the protein. The 90 amino acid extra domain belongs to the so-called type III homology and it is located in the carboxy-terminal half of FN, in between the cell attachment and the heparin binding sites of the protein. The evidence of two mRNAs is provided by the isolation and characterisation of four independent cDNA clones from a library prepared with a synthetic oligonucleotide primer, and it was confirmed by S1 nuclease analysis of cDNA/mRNA hybrids. This kind of analysis also showed that in the human cell line, mRNA I is present at a lower level than mRNA II (the mRNA species without the ED), whilst in human liver, mRNA I is virtually undetectable. Since liver tissue has recently been reported to be the source of plasma FN, our results indicate that the presence of the ED insert could be a particular feature of cellular FN.

Amino Acid Sequence↗
PubMed1984

Expression of a human alpha-globin/fibronectin gene hybrid generates two mRNAs by alternative splicing.

We have isolated genomic clones for human fibronectin (FN), by screening a human gene library with previously isolated FN cDNA clones. We have recently reported two different FN mRNAs, one of them containing an additional 270 nucleotide insert coding for a structural domain ED. Restriction mapping and DNA sequencing of the genomic clones show that the ED type III unit corresponds to exactly one exon in the gene, whilst the two flanking type III units are split in two exons at variable positions. When an alpha-globin/FN gene hybrid construct, containing the ED exon, flanking introns and neighbouring FN exons, is transfected into HeLa cells, two hybrid mRNAs differing by the ED exon are synthesized. These experiments confirmed that the two FN mRNAs observed in vivo arise from the same gene by alternative splicing.

Bacteriophage lambda↗
PubMed1983

Partial primary structure of bovine plasma fibronectin: three types of internal homology.

Approximately one-half of the amino acid sequence (911 amino acid residues out of 1,880 expected) for bovine plasma fibronectin (cold-insoluble globulin) has been determined. Three types of internal homology were identified, showing that a number of partial gene duplications (multiplications) have occurred during the evolution of this protein. Digestion of fibronectin with plasmin results in major fragments with molecular masses of 29, 170, 23, and 6 kilodaltons (kDal). The NH(2)-terminal 29-kDal fragment consists of 259 residues ordered as five mutually homologous domains (type I homology) with two disulfide bonds in each domain. The 170-kDal fragment shows two to three bands after NaDodSO(4) gel electrophoresis, indicating heterogeneity. This fragment contains the gelatin binding site and the strong heparin binding site present in fibronectin. Digestion of the 170-kDal fragment with chymotrypsin liberates a 45-kDal fragment that also binds to gelatin. This fragment contains at least one domain of type I homology and two domains of type II homology. Further digestion of the 170-kDal fragment with chymotrypsin results in the formation of a 30-kDal fragment that retains the heparin binding activity. This fragment contains sequences constituting type III homology. The 23-kDal fragment consists of 178 residues having three domains of type I homology. The 6-kDal fragment consists of two identical peptides of 26 residues, and these two peptides are linked to each other by two disulfide bonds that form the interchain bridges. Another one of the peptides for which the sequence was determined links the COOH-terminus of the 29-kDal fragment to the NH(2)-terminus of the 170-kDal fragment. This and the fact that the COOH-terminal residue of the 6-kDal fragment is a glutamic acid residue order the four plasmin-digestion fragments as 29-, 170-, 23-, and 6-kDal in the intact fibronectin molecule.

Amino Acid Sequence↗
PubMed1983

Isolation and characterization of cDNA clones for human and bovine fibronectins.

A bovine fibronectin (FN) cDNA clone (pFB1) was isolated by screening a cDNA library of calf testis fibroblasts with a synthetic oligonucleotide probe. The probe was a mixture of eight 14-base-long oligonucleotides designed from the amino acid sequence Glu-Cys-Phe-Met-Pro present in the Mr 3,000 COOH-terminal fragment of bovine plasma FN [Petersen, T.E., Thøgersen, H.C., Skorstengaard, K., Vibe-Pedersen, K., Sahl, P., Sottrup-Jensen, L. & Magnusson. S. (1983) Proc. Natl. Acad. Sci. USA 80. 137-141]. pFB1 contained a 1,000 base-pair (bp) insert comprising the complete 3' noncoding sequence (690 bp) and approximately equal to 300 bp of the coding region. The clone pFB1 was used as a radioactive probe in the screening of a human cell line (Hs 578T) cDNA library. Eleven positive cDNA clones were detected, one of which, named pFH1, contained a 2,000-bp insert comprising the complete 3' noncoding region (693 bp) and approximately equal to 1,300 bp of the coding region of human FN. The sequences of the clone pFB1 insert and of the homologous region in clone pFH1 were determined. The nucleotide sequences are 90% homologous. Six amino acid changes were found, clustered in an area connecting two structural domains described in bovine plasma FN. Furthermore, the 204 COOH-terminal amino acid sequence of bovine FN was completed by overlapping two peptide fragments (MrS 3,000 and 23,000). Clone pFH1 was used in estimating the size of human fibronectin mRNA (7,900 bases) through blot hybridization analysis. Southern blot studies suggest that human FN is coded by a unique gene.

Animals↗
PubMed1982

Purification of twelve cyanogen bromide fragments from bovine plasma fibronectin and the amino acid sequence of eight of them. Overlap evidence aligning two plasmic fragments, internal homology in gelatin-binding region and phosphorylation site near C terminus.

Twelve cyanogen bromide fragments (CB1-12) from bovine plasma fibronectin have been isolated and eight of these completely sequenced. Altogether they account for 502 of the total expected 1880 residues in each of the two chains of fibronectin. Four of these fragments (CB1-4) constitute residues 1-289 in fibronectin with CB4 overlapping the N-terminal 29-kDa plasmic fragment to the second plasmic fragment, of 170-kDa in fibronectin. Fragments CB 5-9 are all contained within a 45-kDa gelatin-binding region, which is N-terminal in the 170-kDa fragment. The sequence of two of these five fragments in the 45-kDa fragment (CB7-8) contains two mutually homologous stretches with 57% sequence identity. Another two fragments (CB10-11) are derived from the heparin-binding region of the 170-kDa fragment. CB12 constitutes the C-terminal 13-residue stretch in fibronectin and contains a partly phosphorylated serine residue in the C-terminal sequence: -Arg-Glu-Asp-Ser(P)-Arg-Glu.

Amino Acid Sequence↗