Amino acid sequences and homopolymer-forming ability of the intermediate filament proteins from an invertebrate epithelium.

To provide a basis for studies of the expression of genes encoding the diverse kinds of intermediate-filament (IF) proteins during embryogenesis of Xenopus laevis we have isolated and characterized IF protein cDNA clones. Here we report the identification of two types of Xenopus vimentin, Vim1 and Vim4, with their complete amino acid sequences as deduced from the cloned cDNAs, both of which are expressed during early embryogenesis. In addition, we have obtained two further vimentin cDNAs (Vim2 and 3) which are sequence variants of closely related Vim1. The high evolutionary conservation of the amino acid sequences (Vim1: 458 residues; Mr approximately 52,800; Vim4: 463 residues; Mr approximately 53,500) to avian and mammalian vimentin and, to a lesser degree, to desmin from the same and higher vertebrate species, is emphasized, including conserved oligopeptide motifs in their head domains. Using these cDNAs in RNA blot and ribonuclease protection assays of various embryonic stages, we observed a dramatic increase of vimentin RNA at stage 14, in agreement with immunocytochemical results obtained with antibody VIM-3B4. The significance of very weak mRNA signals detected in earlier stages is discussed in relation to negative immunocytochemical results obtained in these stages. The first appearance of vimentin has been localized to a distinct mesenchymal cell layer underlying the neural plate or tube, respectively. The results are discussed in relation to programs of de novo synthesis of other cytoskeletal proteins in amphibian and mammalian development.

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Developmentally regulated cytokeratin gene in Xenopus laevis.

Molecular and Cellular Biology ◽

10.1128/mcb.5.10.2575 ◽

1985 ◽

Vol 5 (10) ◽

pp. 2575-2581 ◽

Cited By ~ 37

Author(s):

J A Winkles ◽

T D Sargent ◽

D A Parry ◽

E Jonas ◽

I B Dawid

Keyword(s):

Amino Acid ◽

Xenopus Laevis ◽

Intermediate Filament ◽

Type I ◽

Developmentally Regulated ◽

Amino Acid Homology ◽

Intermediate Filament Proteins ◽

Functional Roles ◽

Terminal Domain ◽

Terminal Domains

We have determined the sequence of cloned cDNAs derived from a 1,665-nucleotide mRNA which transiently accumulates during Xenopus laevis embryogenesis. Computer analysis of the deduced amino acid sequence revealed that this mRNA encodes a 47-kilodalton type I intermediate filament subunit, i.e., a cytokeratin. As is common to all intermediate filament subunits so far examined, the predicted polypeptide, named XK70, contains N- and C-terminal domains flanking a central alpha-helical rod domain. The overall amino acid homology between XK70 and a human 50-kilodalton type I keratin is 47%; homology within the alpha-helical domain is 57%. The N-terminal domain, which is not completely contained in our cDNAs, is basic, contains 42% serine plus alanine, and includes five copies of a six-amino-acid repeating unit. The C-terminal domain has a high alpha-helical content and contains a region with sequence homology to the C-terminal domains of other type I and type III intermediate filament proteins. We suggest that different keratin filament subtypes may have different functional roles during amphibian oogenesis and embryogenesis.

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Structural studies on lamin. Similarities and differences between lamin and intermediate-filament proteins

Biochemical Journal ◽

10.1042/bj2380305 ◽

1986 ◽

Vol 238 (1) ◽

pp. 305-308 ◽

Cited By ~ 47

Author(s):

D A D Parry ◽

J F Conway ◽

P M Steinert

Keyword(s):

Amino Acid ◽

Coiled Coil ◽

Amino Acid Sequences ◽

Ionic Interactions ◽

Structural Studies ◽

Intermediate Filament Proteins ◽

Coiled Coil Domain ◽

Similarities And Differences ◽

Almost Continuous

Analysis of the amino acid sequences of lamins A and C has revealed that each chain has an almost continuous heptad-containing coiled-coil domain containing structural regularities in the linear disposition of the acidic and the basic residues. The data suggest that the lamin molecules are two-stranded ropes, that the two chains are parallel to one another and in axial register, and that the molecules aggregate in vivo through periodic ionic interactions. These results indicate that significant changes in stability of the nuclear envelope may be achieved between interphase and mitosis through changes in the degree of phosphorylation of the lamin proteins.

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The amino acid sequence of component 7c, a type II intermediate-filament protein from wool

Biochemical Journal ◽

10.1042/bj2611015 ◽

1989 ◽

Vol 261 (3) ◽

pp. 1015-1022 ◽

Cited By ~ 26

Author(s):

L G Sparrow ◽

C P Robinson ◽

D T W McMahon ◽

M R Rubira

Keyword(s):

Amino Acid ◽

Amino Acid Sequence ◽

Intermediate Filament ◽

Coiled Coil ◽

British Library ◽

Intermediate Filament Protein ◽

Type I ◽

Type Ii ◽

Blocking Group ◽

Intermediate Filament Proteins

Component 7c is one of the four homologous type II intermediate-filament proteins that, by association with the complementary type I proteins, form the microfibrils or intermediate filaments in wool. Component 7c was isolated as the S-carboxymethyl derivative from Merino wool and its amino acid sequence was determined by manual and automatic sequencing of peptides produced by chemical and enzymic cleavage reactions. It is an N-terminally blocked molecule of 491 residues and Mr (not including the blocking group) of 55,600; the nature of the blocking group has not been determined. The predicted secondary structure shows that component 7c conforms to the now accepted pattern for intermediate-filament proteins in having a central rod-like region of approximately 310 residues of coiled-coil alpha-helix flanked by non-helical N-and C-terminal regions. The central region is divided by three non-coiled-coil linking segments into four helical segments 1A, 1B, 2A and 2B. The N-and C-terminal non-helical segments are 109 and 71 residues respectively and are rich in cysteine. Details of procedures use in determining the sequence of component 7c have been deposited as a Supplementary Publication SUP 50152 (65 pages) at the British Library Document Supply Centre, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1989) 257,5. The information comprises: (1) details of chemical and enzymic methods used for cleavage of component 7c, peptides CN1, CN2 and CN3, and various other peptides, (2) details of the procedures used for the fractionation and purification of peptides from (1), including Figures showing the elution profiles from the chromatographic steps used, (3) details of methods used to determine the C-terminal sequence of peptide CN3, and (4) detailed evidence to justify a number of corrections to the previously published sequence.

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Chicken filensin: a lens fiber cell protein that exhibits sequence similarity to intermediate filament proteins

Journal of Cell Science ◽

10.1242/jcs.105.4.1057 ◽

1993 ◽

Vol 105 (4) ◽

pp. 1057-1068 ◽

Cited By ~ 1

Author(s):

S.G. Remington

Keyword(s):

Amino Acid ◽

Intermediate Filament ◽

Fiber Cell ◽

Heptad Repeat ◽

Lens Fiber ◽

Lens Fiber Cell ◽

Intermediate Filament Proteins ◽

Fiber Cells ◽

Amino Terminal ◽

Sequence Identity

Filensin, a 100 kDa, membrane-associated, cytoskeletal protein, is uniquely expressed in the lens fiber cell (Merdes, A., Brunkener, M., Horstmann, H., and Georgatos, S. D. (1991) J. Cell Biol. 115, 397–410). I cloned and sequenced a full-length chicken lens cDNA encoding filensin, also known as CP95 (Ireland, M. and Maisel, H. (1989) Lens and Eye Toxicity Research 6, 623–638). The deduced amino acid sequence of 657 residues contained an internal 280 residue heptad repeat domain with sequence similarities to the rod domain of intermediate filament proteins. The putative filensin rod domain could be divided into three alpha-helical segments (1A, 1B and 2) separated by short, non-helical linkers. The sequence of the amino-terminal end of the filensin rod domain contained the highly conserved intermediate filament segment 1A motif (Conway, J. F. and Parry, D. A. D. (1988) Int. J. Biol. Macromol. 10, 79–98). Allowing conservative amino acid substitutions, the sequence of the carboxy-terminal end of the filensin rod domain was similar to that of the highly conserved intermediate filament rod carboxy terminus. The alpha-helical segments of the shorter filensin rod domain aligned with the corresponding segments of intermediate filament proteins by allowing a gap of four heptad repeats in the amino-terminal half of filensin segment 2. Filensin rod segment 2 contained the characteristic stutter in heptad repeat phasing, nine heptads from the end of the intermediate filament rod. The overall sequence identity between the rod domains of filensin and individual intermediate filament proteins was 20 to 25%, approximately the level of sequence identity observed between intermediate filament proteins of different types. The open reading frame of chicken filensin predicted a 657 amino acid protein with molecular mass of 76 kDa. Embryonic chicken filensin migrated in SDS-PAGE as a triplet of 102, 105 and 109 kDa, while rooster filensin migrated as a 105 and 109 kDa doublet. Antibodies to filensin labeled lens fiber cells but not lens epithelial cells. By immunofluorescence methods filensin was localized to the fiber cell plasma membranes, including the ends of elongated fiber cells.

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The amino acid sequence of chicken muscle desmin provides a common structural model for intermediate filament proteins.

The EMBO Journal ◽

10.1002/j.1460-2075.1982.tb01368.x ◽

1982 ◽

Vol 1 (12) ◽

pp. 1649-1656 ◽

Cited By ~ 268

Author(s):

N. Geisler ◽

K. Weber

Keyword(s):

Amino Acid ◽

Amino Acid Sequence ◽

Intermediate Filament ◽

Structural Model ◽

Intermediate Filament Proteins ◽

Chicken Muscle

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Intracellular assembly and sorting of intermediate filament proteins: role of the 42 amino acid lamin insert

Experimental Cell Research ◽

10.1016/j.yexcr.2004.01.006 ◽

2004 ◽

Vol 295 (1) ◽

pp. 183-193 ◽

Cited By ~ 4

Author(s):

Tim I Mical ◽

Paul W Luther ◽

Mervyn J Monteiro

Keyword(s):

Amino Acid ◽

Intermediate Filament ◽

Intermediate Filament Proteins

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The primary structure of component 8c-1, a subunit protein of intermediate filaments in wool keratin. Relationships with proteins from other intermediate filaments

Biochemical Journal ◽

10.1042/bj2360695 ◽

1986 ◽

Vol 236 (3) ◽

pp. 695-703 ◽

Cited By ~ 60

Author(s):

L M Dowling ◽

W G Crewther ◽

A S Inglis

Keyword(s):

Amino Acid ◽

Intermediate Filaments ◽

Coiled Coil ◽

Amino Acid Sequences ◽

British Library ◽

Type I ◽

Intermediate Filament Proteins ◽

Complete Sequences ◽

Acetyl Group ◽

Keratin Filament

Component 8c-1, one of four highly homologous component-8 subunit proteins present in the microfibrils of wool, was isolated as its S-carboxymethyl derivative and its amino acid sequence was determined. Large peptides were isolated after cleaving the protein chemically or enzymically and the sequence of each was determined with an automatic Sequenator. The peptides were ordered by sequence overlaps and, in some instances, by homology with known sequences from other component-8 subunits. The C-terminal residues were identified by three procedures. Full details of the various procedures used have been deposited as Supplementary Publication SUP 50133 (4 pp.) at the British Library Lending Division, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1986) 233, 5. The result showed that the protein comprises 412 residues and has an Mr, including the N-terminal acetyl group, of 48,300. The sequence of residues 98-200 of component 8c-1 was found to correspond to the partial or complete sequences of four homologous type I helical segments previously isolated from helical fragments recovered from chymotryptic digests of microfibrillar proteins of wool [Crewther & Dowling (1971) Appl. Polym. Symp. 18, 1-20; Crewther, Gough, Inglis & McKern (1978) Text. Res. J. 48, 160-162; Gough, Inglis & Crewther (1978) Biochem. J. 173, 385]. Considered in relation to amino acid sequences of other intermediate-filament proteins, the sequence is in accord with the view that keratin filament proteins are of two types [Hanukoglu & Fuchs (1983) Cell (Cambridge, Mass.) 33, 915-924]. Filament proteins from non-keratinous tissues, such as desmin, vimentin, neurofilament proteins and the glial fibrillary acidic protein, which form monocomponent filaments, constitute a third type. It is suggested that as a whole the proteins from intermediate filaments be classed as filamentins, the three types at present identified forming subgroups of this class. The significant homologies between types I, II and III occur almost exclusively in segments of the chain that have been identified as having a coiled-coil structure together with the relatively short sections connecting these segments. The non-coiled-coil segments at the C- and N-termini show no significant homology between types, nor is homology in these segments apparent in all members of one type. Component 8c-1 does not show homology in its terminal segments with the known sequence of any other filamentin.(ABSTRACT TRUNCATED AT 400 WORDS)

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