scholarly journals Cytokeratin 8: The Dominant Type II Intermediate Filament Protein in Lung Cancer

10.5772/34237 ◽  
2012 ◽  
Author(s):  
Nobuhiro Kanaji ◽  
Akihito Kubo ◽  
Shuji Bandoh ◽  
Tomoya Ishii ◽  
Jiro Fujita ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Intermediate Filament ◽  
Intermediate Filament Protein ◽  
Type Ii ◽  
Dominant Type ◽  
Filament Protein

scholarly journals A nontetrameric species is the major soluble form of keratin in Xenopus oocytes and rabbit reticulocyte lysates.

1996 ◽  
Vol 132 (1) ◽  
pp. 153-165 ◽  
Author(s):  
J B Bachant ◽  
M W Klymkowsky
Keyword(s):  
Molecular Weight ◽  
Intermediate Filament ◽  
Apparent Molecular Weight ◽  
Soluble Form ◽  
Intermediate Filament Protein ◽  
Type I ◽  
Type Ii ◽  
Cell Biol ◽  
Reticulocyte Lysates ◽  
Filament Protein

Inside the interphase cell, approximately 5% of the total intermediate filament protein exists in a soluble form. Past studies using velocity gradient sedimentation (VGS) indicate that soluble intermediate filament protein exists as an approximately 7 S tetrameric species. While studying intermediate filament assembly dynamics in the Xenopus oocyte, we used both VGS and size-exclusion chromatography (SEC) to analyze the soluble form of keratin. Previous studies (Coulombe, P. A., and E. Fuchs. 1990. J. Cell Biol. 111:153) report that tetrameric keratins migrate on SEC with an apparent molecular weight of approximately 150,000; the major soluble form of keratin in the oocyte, in contrast, migrates with an apparent molecular weight of approximately 750,000. During oocyte maturation, the keratin system disassembles into a soluble form (Klymkowsky, M. W., L. A. Maynell, and C. Nislow. 1991. J. Cell Biol. 114:787) and the amount of the 750-kD keratin complex increases dramatically. Immunoprecipitation analysis of soluble keratin from matured oocytes revealed the presence of type I and type II keratins, but no other stoichiometrically associated polypeptides, suggesting that the 750-kD keratin complex is composed solely of keratin. To further study the formation of the 750-kD keratin complex, we used rabbit reticulocyte lysates (RRL). The 750-kD keratin complex was formed in RRLs contranslating type I and type II Xenopus keratins, but not when lysates translated type I or type II keratin RNAs alone. The 750-kD keratin complex could be formed posttranslationally in an ATP-independent manner when type I and type II keratin translation reactions were mixed. Under conditions of prolonged incubation, such as occur during VGS analysis, the 750-kD keratin complex disassembled into a 7 S (by VGS), 150-kD (by SEC) form. In urea denaturation studies, the 7 S/150-kD form could be further disassembled into an 80-kD species that consists of cofractionating dimeric and monomeric keratin. Based on these results, the 750-kD species appears to be a supratetrameric complex of keratins and is the major, soluble form of keratin in both prophase and M-phase oocytes, and RRL reactions.

scholarly journals The Intermediate Filament Protein Vimentin Is a New Target for Epigallocatechin Gallate

2005 ◽  
Vol 280 (17) ◽  
pp. 16882-16890 ◽  
Author(s):  
Svetlana Ermakova ◽  
Bu Young Choi ◽  
Hong Seok Choi ◽  
Bong Seok Kang ◽  
Ann M. Bode ◽  
...  
Keyword(s):  
Intermediate Filament ◽  
Epigallocatechin Gallate ◽  
Intermediate Filament Protein ◽  
Filament Protein

A cDNA from Drosophila melanogaster encodes a lamin C-like intermediate filament protein

1993 ◽  
Vol 104 (4) ◽  
pp. 1263-1272 ◽  
Author(s):  
C.A. Bossie ◽  
M.M. Sanders
Keyword(s):  
Drosophila Melanogaster ◽  
Intermediate Filament ◽  
Blot Analysis ◽  
Polytene Chromosomes ◽  
Intermediate Filament Protein ◽  
Chromosome 2 ◽  
Cross Hybridization ◽  
Intermediate Filament Proteins ◽  
Nuclear Lamins ◽  
Filament Protein

A novel intermediate filament cDNA, pG-IF, has been isolated from a Drosophila melanogaster embryonic expression library screened with a polyclonal antiserum produced against a 46 kDa cytoskeletal protein isolated from Kc cells. This 46 kDa protein is known to be immunologically related to vertebrate intermediate filament proteins. The screen resulted in the isolation of four different cDNA groups. Of these, one has been identified as the previously characterized Drosophila nuclear lamin cDNA, Dm0, and a second, pG-IF, demonstrates homology to Dm0 by cross hybridization on Southern blots. DNA sequence analysis reveals that pG-IF encodes a newly identified intermediate filament protein in Drosophila. Its nucleotide sequence is highly homologous to nuclear lamins with lower homology to cytoplasmic intermediate filament proteins. pG-IF predicts a protein of 621 amino acids with a predicted molecular mass of 69,855 daltons. In vitro transcription and translation of pG-IF yielded a protein with a SDS-PAGE estimated molecular weight of approximately 70 kDa. It contains sequence principles characteristic of class V intermediate filament proteins. Its near neutral pI (6.83) and the lack of a terminal CaaX motif suggests that it may represent a lamin C subtype in Drosophila. In situ hybridization to polytene chromosomes detects one band of hybridization on the right arm of chromosome 2 at or near 51A. This in conjunction with Southern blot analysis of various genomic digests suggests one or more closely placed genes while Northern blot analysis detects two messages in Kc cells.

The presence or absence of a vimentin-type intermediate filament network affects the shape of the nucleus in human SW-13 cells

1994 ◽  
Vol 107 (6) ◽  
pp. 1593-1607 ◽  
Author(s):  
A.J. Sarria ◽  
J.G. Lieber ◽  
S.K. Nordeen ◽  
R.M. Evans
Keyword(s):  
Electron Microscopy ◽  
Intermediate Filament ◽  
Nuclear Morphology ◽  
Intermediate Filament Protein ◽  
Mosaic Pattern ◽  
Expression Plasmid ◽  
Vimentin Expression ◽  
Filament System ◽  
Filament Protein ◽  
Filament Network

Human SW-13 cells express the intermediate filament protein vimentin in a mosaic pattern (Hedberg, K. K. and Chen, L. B. (1986). Exp. Cell Res. 163, 509–517). We have isolated SW-13 clones that do (vim+) or do not (vim-) synthesize vimentin as analyzed using anti-intermediate filament immunofluorescence, electron microscopy and two-dimensional gel analysis of detergent-extracted preparations. Vimentin is the only cytoplasmic intermediate filament protein present in the vim+ cells, and the vim- cells do not contain any detectable cytoplasmic intermediate filament system. The presence or absence of intermediate filaments did not observably affect the distribution of mitochondria, endoplasmic reticulum, microtubules or actin stress fibers when these structures were visualized by fluorescence microscopy. However, electron microscopy and anti-lamin A/C immunofluorescence studies showed that nuclear morphology in vim- cells was frequently characterized by large folds or invaginations, while vim+ cells had a more regular or smooth nuclear shape. When vim- cells were transfected with a mouse vimentin expression plasmid, the synthesis of a mouse vimentin filament network restored the smooth nuclear morphology characteristic of vim+ cells. Conversely, when vim+ cells were transfected with a carboxy-terminally truncated mutant vimentin, expression of the mutant protein disrupted the organization of the endogenous vimentin filaments and resulted in nuclei with a prominently invaginated morphology. These results indicated that in SW-13 cells the vimentin filament system affects the shape of the nucleus.

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