scholarly journals Structures of the ß-Keratin Filaments and Keratin Intermediate Filaments in the Epidermal Appendages of Birds and Reptiles (Sauropsids)

Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 591
Author(s):  
David A.D. Parry
Keyword(s):  
Physical Properties ◽  
Intermediate Filaments ◽  
Epidermal Differentiation ◽  
Defence Mechanisms ◽  
Epidermal Differentiation Complex ◽  
Keratin Filaments ◽  
The Matrix ◽  
The Individual ◽  
Keratin Intermediate Filaments ◽  
Terminal Domains

The epidermal appendages of birds and reptiles (the sauropsids) include claws, scales, and feathers. Each has specialized physical properties that facilitate movement, thermal insulation, defence mechanisms, and/or the catching of prey. The mechanical attributes of each of these appendages originate from its fibril-matrix texture, where the two filamentous structures present, i.e., the corneous ß-proteins (CBP or ß-keratins) that form 3.4 nm diameter filaments and the α-fibrous molecules that form the 7–10 nm diameter keratin intermediate filaments (KIF), provide much of the required tensile properties. The matrix, which is composed of the terminal domains of the KIF molecules and the proteins of the epidermal differentiation complex (EDC) (and which include the terminal domains of the CBP), provides the appendages, with their ability to resist compression and torsion. Only by knowing the detailed structures of the individual components and the manner in which they interact with one another will a full understanding be gained of the physical properties of the tissues as a whole. Towards that end, newly-derived aspects of the detailed conformations of the two filamentous structures will be discussed and then placed in the context of former knowledge.

scholarly journals Discovery of keratin function and role in genetic diseases: the year that 1991 was

2016 ◽  
Vol 27 (18) ◽  
pp. 2807-2810 ◽  
Author(s):  
Pierre A. Coulombe
Keyword(s):  
Intermediate Filaments ◽  
Cell Biology ◽  
Essential Role ◽  
Genetic Diseases ◽  
Structure And Function ◽  
Mechanical Support ◽  
25Th Anniversary ◽  
Keratin Filaments ◽  
And Function ◽  
Keratin Intermediate Filaments

In 1991, a set of transgenic mouse studies took the fields of cell biology and dermatology by storm in providing the first credible evidence that keratin intermediate filaments play a unique and essential role in the structural and mechanical support in keratinocytes of the epidermis. Moreover, these studies intimated that mutations altering the primary structure and function of keratin filaments underlie genetic diseases typified by cellular fragility. This Retrospective on how these studies came to be is offered as a means to highlight the 25th anniversary of these discoveries.

scholarly journals Keratins and plakin family cytolinker proteins control the length of epithelial microridge protrusions

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Yasuko Inaba ◽  
Vasudha Chauhan ◽  
Aaron Paul van Loon ◽  
Lamia Saiyara Choudhury ◽  
Alvaro Sagasti
Keyword(s):  
Intermediate Filaments ◽  
Intermediate Filament ◽  
Actin Filaments ◽  
Actin Binding ◽  
Protein Levels ◽  
Skin Cells ◽  
Keratin Filaments ◽  
Actin Binding Domain ◽  
Cytoskeletal Elements ◽  
Keratin Intermediate Filaments

Actin filaments and microtubules create diverse cellular protrusions, but intermediate filaments, the strongest and most stable cytoskeletal elements, are not known to directly participate in the formation of protrusions. Here we show that keratin intermediate filaments directly regulate the morphogenesis of microridges, elongated protrusions arranged in elaborate maze-like patterns on the surface of mucosal epithelial cells. We found that microridges on zebrafish skin cells contained both actin and keratin filaments. Keratin filaments stabilized microridges, and overexpressing keratins lengthened them. Envoplakin and periplakin, plakin family cytolinkers that bind F-actin and keratins, localized to microridges, and were required for their morphogenesis. Strikingly, plakin protein levels directly dictate microridge length. An actin-binding domain of periplakin was required to initiate microridge morphogenesis, whereas periplakin-keratin binding was required to elongate microridges. These findings separate microridge morphogenesis into distinct steps, expand our understanding of intermediate filament functions, and identify microridges as protrusions that integrate actin and intermediate filaments.

scholarly journals 14-3-3 targets keratin intermediate filaments to mechanically sensitive cell–cell contacts

2020 ◽  
Vol 31 (9) ◽  
pp. 930-943 ◽  
Author(s):  
Richard A. Mariani ◽  
Shalaka Paranjpe ◽  
Radek Dobrowolski ◽  
Gregory F. Weber
Keyword(s):  
Intermediate Filaments ◽  
Intermediate Filament ◽  
Sensitive Cell ◽  
Filament Dynamics ◽  
Keratin 19 ◽  
Keratin Filaments ◽  
Novel Association ◽  
Keratin Intermediate Filaments ◽  
Cell Cell

14-3-3 serves as a major regulator of keratin intermediate filament dynamics in vivo. Migratory mesendoderm tissue of the Xenopus embryo is used to show that the dynamic reorganization of keratin filaments, a consequence of force on cell-cell adhesions, is mediated by a novel association between 14-3-3 and Keratin 19.

scholarly journals Keratins and Plakin family cytolinker proteins control the length of epithelial microridge protrusions

2020 ◽  
Author(s):  
Yasuko Inaba ◽  
Vasudha Chauhan ◽  
Aaron Paul van Loon ◽  
Lamia Saiyara Choudhury ◽  
Alvaro Sagasti
Keyword(s):  
Intermediate Filaments ◽  
Actin Filaments ◽  
Actin Binding ◽  
Protein Levels ◽  
Skin Cells ◽  
Keratin Filaments ◽  
Actin Binding Domain ◽  
Stable Class ◽  
Cytoskeletal Elements ◽  
Keratin Intermediate Filaments

ABSTRACTActin filaments and microtubules create diverse cellular protrusions, but intermediate filaments, the strongest and most stable class of cytoskeletal elements, are not known to directly participate in the formation of protrusions. Here we show that Keratin intermediate filaments directly regulate the morphogenesis of microridges, elongated protrusions from mucosal epithelial cells arranged in elaborate fingerprint-like patterns. Developing microridges on zebrafish skin cells contained both Actin and Keratin filaments. Keratin filaments maintained microridges upon F-actin disruption, and overexpressing Keratins lengthened microridges. Envoplakin and Periplakin, Plakin family cytolinkers that bind to F-actin and Keratins, localized to microridges and were required for their morphogenesis. Strikingly, Plakin protein levels directly determined microridge length. An actin-binding domain of Periplakin was required to initiate microridge morphogenesis, whereas Periplakin-Keratin binding was required to stabilize and elongate microridges. Our results thus separate microridge morphogenesis into two steps with differential requirements for cytoskeletal elements, expand our understanding of intermediate filament functions, and identify microridges as cellular protrusions that integrate actin and intermediate filaments.

COLMONOY 805

Alloy Digest ◽  
1998 ◽  
Vol 47 (12) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Abrasion Resistance ◽  
Coarse Particles ◽  
Powder Metal ◽  
Chromium Boride ◽  
Nickel Chromium ◽  
The Matrix

Abstract Colmonoy 805 is a nickel-chromium-boron alloy with coarse particles of chromium boride added to give it excellent sliding-type abrasion resistance. The alloy contains chromium boride in the matrix as large added particles. It is supplied only as a crushed powder for application with Colmonoy’s Fuseweld process. This datasheet provides information on composition, physical properties, microstructure, and elasticity. It also includes information on corrosion resistance as well as joining and powder metal forms.Filing Code: Ni-233. Producer or source: Wall Colmonoy Corporation. Originally published September 1976, revised December 1998.

scholarly journals Selective sweep for an enhancer involucrin allele identifies skin barrier adaptation out of Africa

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mary Elizabeth Mathyer ◽  
Erin A. Brettmann ◽  
Alina D. Schmidt ◽  
Zane A. Goodwin ◽  
Inez Y. Oh ◽  
...  
Keyword(s):  
Selective Sweep ◽  
Skin Barrier ◽  
Human Migration ◽  
Epidermal Differentiation ◽  
Human Populations ◽  
Epidermal Differentiation Complex ◽  
Regulatory Module ◽  
Reporter Assays ◽  
Out Of Africa

AbstractThe genetic modules that contribute to human evolution are poorly understood. Here we investigate positive selection in the Epidermal Differentiation Complex locus for skin barrier adaptation in diverse HapMap human populations (CEU, JPT/CHB, and YRI). Using Composite of Multiple Signals and iSAFE, we identify selective sweeps for LCE1A-SMCP and involucrin (IVL) haplotypes associated with human migration out-of-Africa, reaching near fixation in European populations. CEU-IVL is associated with increased IVL expression and a known epidermis-specific enhancer. CRISPR/Cas9 deletion of the orthologous mouse enhancer in vivo reveals a functional requirement for the enhancer to regulate Ivl expression in cis. Reporter assays confirm increased regulatory and additive enhancer effects of CEU-specific polymorphisms identified at predicted IRF1 and NFIC binding sites in the IVL enhancer (rs4845327) and its promoter (rs1854779). Together, our results identify a selective sweep for a cis regulatory module for CEU-IVL, highlighting human skin barrier evolution for increased IVL expression out-of-Africa.

scholarly journals Interfacial Aspects of Metal Matrix Composites Prepared from Liquid Metals and Aqueous Solutions: A Review

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1400
Author(s):  
Peter Baumli
Keyword(s):  
Aqueous Solutions ◽  
Physical Properties ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Liquid Metals ◽  
Interfacial Phenomena ◽  
Matrix Composites ◽  
Good Adhesion ◽  
Mechanical And Physical Properties ◽  
The Matrix

The paper reviews the preparation of the different metallic nanocomposites. In the preparation of composites, especially in the case of nanocomposites, interfacial phenomena play an important role. This review summarizes the literature on various interfacial phenomena, such as wettability and reactivity in the case of casting techniques and colloidal behavior in the case of electrochemical and electroless methods. The main contribution of this work lies in the evaluation of collected interfacial phenomena and difficulties in the production of metal matrix composites, for both nano-sized and micro-sized reinforcements. This study can guide the composite maker in choosing the best criteria for producing metal matrix composites, which means a real interface with good adhesion between the matrix and the reinforcement. This criterion results in desirable mechanical and physical properties and homogenous dispersion of the reinforcement in the matrix.

scholarly journals Lis1 is essential for cortical microtubule organization and desmosome stability in the epidermis

2011 ◽  
Vol 194 (4) ◽  
pp. 631-642 ◽  
Author(s):  
Kaelyn D. Sumigray ◽  
Hsin Chen ◽  
Terry Lechler
Keyword(s):  
Cortical Microtubule ◽  
Cell Types ◽  
Epidermal Differentiation ◽  
Cell Cortex ◽  
Microtubule Organization ◽  
Specific Subset ◽  
Keratin Filaments ◽  
Perinatal Lethality ◽  
Cytoskeletal Networks ◽  
Centrosomal Proteins

Desmosomes are cell–cell adhesion structures that integrate cytoskeletal networks. In addition to binding intermediate filaments, the desmosomal protein desmoplakin (DP) regulates microtubule reorganization in the epidermis. In this paper, we identify a specific subset of centrosomal proteins that are recruited to the cell cortex by DP upon epidermal differentiation. These include Lis1 and Ndel1, which are centrosomal proteins that regulate microtubule organization and anchoring in other cell types. This recruitment was mediated by a region of DP specific to a single isoform, DPI. Furthermore, we demonstrate that the epidermal-specific loss of Lis1 results in dramatic defects in microtubule reorganization. Lis1 ablation also causes desmosomal defects, characterized by decreased levels of desmosomal components, decreased attachment of keratin filaments, and increased turnover of desmosomal proteins at the cell cortex. This contributes to loss of epidermal barrier activity, resulting in completely penetrant perinatal lethality. This work reveals essential desmosome-associated components that control cortical microtubule organization and unexpected roles for centrosomal proteins in epidermal function.

Extracellular regulation of BMP signaling: welcome to the matrix

2017 ◽  
Vol 45 (1) ◽  
pp. 173-181 ◽  
Author(s):  
Georg Sedlmeier ◽  
Jonathan P. Sleeman
Keyword(s):  
Extracellular Matrix ◽  
Physical Properties ◽  
Bone Morphogenetic Protein ◽  
Bmp Signaling ◽  
Intracellular Level ◽  
Morphogenetic Protein ◽  
The Matrix ◽  
Mechanical Barrier

Given its importance in development and homeostasis, bone morphogenetic protein (BMP) signaling is tightly regulated at the extra- and intracellular level. The extracellular matrix (ECM) was initially thought to act as a passive mechanical barrier that sequesters BMPs. However, a new understanding about how the ECM plays an instructive role in regulating BMP signaling is emerging. In this mini-review, we discuss various ways in which the biochemical and physical properties of the ECM regulate BMP signaling.

scholarly journals Involvement of transcribed lncRNA uc.291 and SWI/SNF complex in cutaneous squamous cell carcinoma

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
M. Mancini ◽  
A. Cappello ◽  
R. Pecorari ◽  
A. M. Lena ◽  
M. Montanaro ◽  
...  
Keyword(s):  
Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Expression Patterns ◽  
Chromatin Accessibility ◽  
Cutaneous Squamous Cell Carcinoma ◽  
Epidermal Differentiation ◽  
Differentiation Process ◽  
Clinical Biomarkers ◽  
Epidermal Differentiation Complex

AbstractWhile non-melanoma skin cancers (NMSCs) are the most common tumours in humans, only the sub-type cutaneous squamous cell carcinoma (cSCC), might become metastatic with high lethality. We have recently identified a regulatory pathway involving the lncRNA transcript uc.291 in controlling the expression of epidermal differentiation complex genes via the interaction with ACTL6A, a component of the chromatin remodelling complex SWI/SNF. Since transcribed ultra-conserved regions (T-UCRs) are expressed in normal tissues and are deregulated in tumorigenesis, here we hypothesize a potential role for dysregulation of this axis in cSCC, accounting for the de-differentiation process observed in aggressive poorly differentiated cutaneous carcinomas. We therefore analysed their expression patterns in human tumour biopsies at mRNA and protein levels. The results suggest that by altering chromatin accessibility of the epidermal differentiation complex genes, down-regulation of uc.291 and BRG1 expression contribute to the de-differentiation process seen in keratinocyte malignancy. This provides future direction for the identification of clinical biomarkers in cutaneous SCC. Analysis of publicly available data sets indicates that the above may also be a general feature for SCCs of different origins.

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