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

1989 ◽  
Vol 261 (3) ◽  
pp. 1015-1022 ◽  
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.

scholarly journals A High Molecular Weight Intermediate Filament-associated Protein in BHK-21 Cells Is Nestin, a Type VI Intermediate Filament Protein

1999 ◽  
Vol 274 (14) ◽  
pp. 9881-9890 ◽  
Author(s):  
Peter M. Steinert ◽  
Ying-Hao Chou ◽  
Veena Prahlad ◽  
David A. D. Parry ◽  
Lyuben N. Marekov ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Intermediate Filament ◽  
Intermediate Filament Protein ◽  
Filament Protein

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 Expression of Cytokeratin 6 and 16 in Middle Ear Cholesteatoma

2021 ◽  
Vol 9 (B) ◽  
pp. 1323-1328
Author(s):  
Jacky Munilson ◽  
Yan Edward ◽  
Lorensia Fitra Dwita ◽  
Hirowati Ali
Keyword(s):  
Middle Ear ◽  
Clinical Manifestations ◽  
Bone Destruction ◽  
Intermediate Filament Protein ◽  
Type I ◽  
Type Ii ◽  
Cross Sectional ◽  
Middle Ear Cholesteatoma ◽  
The Difference ◽  
Filament Protein

BACKGROUND: Cholesteatoma is hyperproliferative because of the response of direct biomechanical trauma, and inflammation processes then lead to temporal bone destruction with some clinical manifestations of complications. The hyperproliferation mechanism occurred because of the activation of intermediate filament protein type I and type II known as cytokeratin (CK). AIM: This study aimed to examine the expression CK 6 and CK 16 in cholesteatoma. METHODS: This is a cross-sectional comparative study. Cholesteatoma specimens obtained from 15 patients who underwent surgery were considered as the case, and 15 normal retro-auricular skins were considered as the control. All samples were examined for expression through immunohistochemistry and scored using the immunoreactivity score. Data were analyzed using SPSS via χ2 test, and the difference was significant (p < 0.05). RESULTS: The expression of CK 6 was high in cholesteatoma (33.3%) and low in retro-auricular skin. The expression of CK 16 was high in all samples of cholesteatoma and mostly high in the retro-auricular skin; both expressions were statistically significant (p < 0.05). CONCLUSION: The expression of CK 6 and CK 16 in cholesteatoma was higher than in normal retro-auricular skin.

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