scholarly journals Isolation, sequence, and expression of a human keratin K5 gene: transcriptional regulation of keratins and insights into pairwise control.

1989 ◽  
Vol 9 (9) ◽  
pp. 3685-3697 ◽  
Author(s):  
R Lersch ◽  
V Stellmach ◽  
C Stocks ◽  
G Giudice ◽  
E Fuchs

The mitotically active basal layers of most stratified squamous epithelia express 10 to 30% of their total protein as keratin. The two keratins specifically expressed in these cells are the type II keratin K5 (58 kilodaltons) and its corresponding partner, type I keratin K14 (50 kilodaltons), both of which are essential for the formation of 8-nm filaments. Dissecting the molecular mechanisms underlying the coordinate regulation of the two keratins is an important first step in understanding epidermal differentiation and in designing promoters that will enable delivery and expression of foreign gene products in stratified squamous epithelia, e.g., skin. Previously, we reported the sequence of the gene encoding human K14 (D. Marchuk, S. McCrohon, and E. Fuchs, Cell 39:491-498, 1984; Marchuk et al., Proc. Natl. Acad. Sci. USA 82:1609-1613, 1985). We have now isolated and characterized the gene encoding human K5. The sequence of the coding portion of this gene matched perfectly with that of a partial K5 cDNA sequence obtained from a cultured human epidermal library (R. Lersch and E. Fuchs, Mol. Cell. Biol. 8:486-493, 1988), and gene transfection studies indicated that the gene is functional. Nuclear runoff experiments demonstrated that the K5 and K14 genes were both transcribed at dramatically higher levels in cultured human epidermal cells than in fibroblasts, indicating that at least part of the regulation of the expression of this keratin pair is at the transcriptional level. When the K5 gene was transfected transiently into NIH 3T3 fibroblasts, foreign expression of the gene caused the appearance of endogenous mouse K14 and the subsequent formation of a keratin filament array in the cells. In this case, transcriptional changes did not appear to be involved in the regulation, suggesting that there may be multiple control mechanisms underlying the pairwise expression of keratins.

1989 ◽  
Vol 9 (9) ◽  
pp. 3685-3697
Author(s):  
R Lersch ◽  
V Stellmach ◽  
C Stocks ◽  
G Giudice ◽  
E Fuchs

The mitotically active basal layers of most stratified squamous epithelia express 10 to 30% of their total protein as keratin. The two keratins specifically expressed in these cells are the type II keratin K5 (58 kilodaltons) and its corresponding partner, type I keratin K14 (50 kilodaltons), both of which are essential for the formation of 8-nm filaments. Dissecting the molecular mechanisms underlying the coordinate regulation of the two keratins is an important first step in understanding epidermal differentiation and in designing promoters that will enable delivery and expression of foreign gene products in stratified squamous epithelia, e.g., skin. Previously, we reported the sequence of the gene encoding human K14 (D. Marchuk, S. McCrohon, and E. Fuchs, Cell 39:491-498, 1984; Marchuk et al., Proc. Natl. Acad. Sci. USA 82:1609-1613, 1985). We have now isolated and characterized the gene encoding human K5. The sequence of the coding portion of this gene matched perfectly with that of a partial K5 cDNA sequence obtained from a cultured human epidermal library (R. Lersch and E. Fuchs, Mol. Cell. Biol. 8:486-493, 1988), and gene transfection studies indicated that the gene is functional. Nuclear runoff experiments demonstrated that the K5 and K14 genes were both transcribed at dramatically higher levels in cultured human epidermal cells than in fibroblasts, indicating that at least part of the regulation of the expression of this keratin pair is at the transcriptional level. When the K5 gene was transfected transiently into NIH 3T3 fibroblasts, foreign expression of the gene caused the appearance of endogenous mouse K14 and the subsequent formation of a keratin filament array in the cells. In this case, transcriptional changes did not appear to be involved in the regulation, suggesting that there may be multiple control mechanisms underlying the pairwise expression of keratins.


2002 ◽  
Vol 227 (5) ◽  
pp. 301-314 ◽  
Author(s):  
Asish K. Ghosh

Type I collagen, the major component of extracellular matrix in skin and other tissues, is a heterotrimer of two α1 and one α2 collagen polypeptides. The synthesis of both chains is highly regulated by different cytokines at the transcriptional level. Excessive synthesis and deposition of collagen in the dermal region causes thick and hard skin, a clinical manifestation of scleroderma. To better understand the causes of scleroderma or other tissue fibrosis, it is very Important to investigate the molecular mechanisms that cause upregulation of the Type I collagen synthesis in these tissues. Several cis-acting regulatory elements and trans-acting protein factors, which are involved in basal as well as cytokine-modulated Type I collagen gene expression, have been identified and characterized. Hypertranscription of Type I collagen in scleroderma skin fibroblasts may be due to abnormal activities of different positive or negative transcription factors In response to different abnormally induced signaling pathways. In this review, I discuss the present day understanding about the involvement of different factors in the regulation of basal as well as cytokine-modulated Type I collagen gene expression and its implication in scleroderma research.


1986 ◽  
Vol 6 (2) ◽  
pp. 539-548 ◽  
Author(s):  
A RayChaudhury ◽  
D Marchuk ◽  
M Lindhurst ◽  
E Fuchs

We have isolated and subcloned three separate segments of human DNA which share strong sequence homology with a previously sequenced gene encoding a type I keratin, K14 (50 kilodaltons). Restriction endonuclease mapping has demonstrated that these three genes are tightly linked chromosomally, whereas the K14 gene appears to be separate. As judged by positive hybridization-translation and Northern blot analyses, the central linked gene encodes a keratin, K17, which is expressed in abundance with K14 and two other type I keratins in cultured human epidermal cells. None of these other epidermal keratin mRNAs appears to be generated from the K17 gene through differential splicing of its transcript. The sequence of the K17 gene reveals striking homologies not only with the coding portions and intron positions of the K14 gene, but also with its 5'-noncoding and 5'-upstream sequences. These similarities may provide an important clue in elucidating the molecular mechanisms underlying the coexpression of the two genes.


1986 ◽  
Vol 6 (2) ◽  
pp. 539-548
Author(s):  
A RayChaudhury ◽  
D Marchuk ◽  
M Lindhurst ◽  
E Fuchs

We have isolated and subcloned three separate segments of human DNA which share strong sequence homology with a previously sequenced gene encoding a type I keratin, K14 (50 kilodaltons). Restriction endonuclease mapping has demonstrated that these three genes are tightly linked chromosomally, whereas the K14 gene appears to be separate. As judged by positive hybridization-translation and Northern blot analyses, the central linked gene encodes a keratin, K17, which is expressed in abundance with K14 and two other type I keratins in cultured human epidermal cells. None of these other epidermal keratin mRNAs appears to be generated from the K17 gene through differential splicing of its transcript. The sequence of the K17 gene reveals striking homologies not only with the coding portions and intron positions of the K14 gene, but also with its 5'-noncoding and 5'-upstream sequences. These similarities may provide an important clue in elucidating the molecular mechanisms underlying the coexpression of the two genes.


Author(s):  
Yoshiyuki Rikitake

Abstract The apelin (APJ) receptor was originally cloned as a gene encoding a putative G protein-coupled receptor related to angiotensin receptor type I. To date, two endogenous peptide ligands for APJ have been identified: apelin and elabela/Toddler. The apelin/APJ system regulates blood pressure and vascular tone. The endothelial and smooth muscle apelin/APJ systems exert opposite actions in the regulation of vascular tone. Binding of apelin to endothelial APJ promotes the release of vasodilators, such as nitric oxide and prostacyclin, leading to vasodilation. Alternatively, binding of apelin to smooth muscle APJ induces vasoconstriction, although the molecular mechanisms of the apelin-induced vasoconstriction are poorly understood. Recently, a critical role for interaction of APJ with α1-adrenergic receptor in the apelin-induced vasoconstriction was reported. The action of apelin on vascular tone may depend upon blood vessel type or pathological condition. Although the apelin/APJ system could serve as a potential therapeutic target for hypertension and cardiovascular disease, the role of this system in various cell types appears to be complicated.


1992 ◽  
Vol 84 (4) ◽  
pp. 561-567 ◽  
Author(s):  
Poul E. Jensen ◽  
Michael Kristensen ◽  
Tine Hoff ◽  
Jan Lehmbeck ◽  
Bjarne M. Stummann ◽  
...  

2021 ◽  
Vol 22 (4) ◽  
pp. 1861
Author(s):  
Jemima Seidenberg ◽  
Mara Stellato ◽  
Amela Hukara ◽  
Burkhard Ludewig ◽  
Karin Klingel ◽  
...  

Background: Pathological activation of cardiac fibroblasts is a key step in development and progression of cardiac fibrosis and heart failure. This process has been associated with enhanced autophagocytosis, but molecular mechanisms remain largely unknown. Methods and Results: Immunohistochemical analysis of endomyocardial biopsies showed increased activation of autophagy in fibrotic hearts of patients with inflammatory cardiomyopathy. In vitro experiments using mouse and human cardiac fibroblasts confirmed that blockade of autophagy with Bafilomycin A1 inhibited fibroblast-to-myofibroblast transition induced by transforming growth factor (TGF)-β. Next, we observed that cardiac fibroblasts obtained from mice overexpressing transcription factor Fos-related antigen 2 (Fosl-2tg) expressed elevated protein levels of autophagy markers: the lipid modified form of microtubule-associated protein 1A/1B-light chain 3B (LC3BII), Beclin-1 and autophagy related 5 (Atg5). In complementary experiments, silencing of Fosl-2 with antisense GapmeR oligonucleotides suppressed production of type I collagen, myofibroblast marker alpha smooth muscle actin and autophagy marker Beclin-1 in cardiac fibroblasts. On the other hand, silencing of either LC3B or Beclin-1 reduced Fosl-2 levels in TGF-β-activated, but not in unstimulated cells. Using a cardiac hypertrophy model induced by continuous infusion of angiotensin II with osmotic minipumps, we confirmed that mice lacking either Fosl-2 (Ccl19CreFosl2flox/flox) or Atg5 (Ccl19CreAtg5flox/flox) in stromal cells were protected from cardiac fibrosis. Conclusion: Our findings demonstrate that Fosl-2 regulates autophagocytosis and the TGF-β-Fosl-2-autophagy axis controls differentiation of cardiac fibroblasts. These data provide a new insight for the development of pharmaceutical targets in cardiac fibrosis.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Joel M. J. Tan ◽  
Monica E. Garner ◽  
James M. Regeimbal ◽  
Catherine J. Greene ◽  
Jorge D. Rojas Márquez ◽  
...  

AbstractThe type I interferon (IFN) signaling pathway has important functions in resistance to viral infection, with the downstream induction of interferon stimulated genes (ISG) protecting the host from virus entry, replication and spread. Listeria monocytogenes (Lm), a facultative intracellular foodborne pathogen, can exploit the type I IFN response as part of their pathogenic strategy, but the molecular mechanisms involved remain unclear. Here we show that type I IFN suppresses the antibacterial activity of phagocytes to promote systemic Lm infection. Mechanistically, type I IFN suppresses phagosome maturation and proteolysis of Lm virulence factors ActA and LLO, thereby promoting phagosome escape and cell-to-cell spread; the antiviral protein, IFN-induced transmembrane protein 3 (IFITM3), is required for this type I IFN-mediated alteration. Ifitm3−/− mice are resistant to systemic infection by Lm, displaying decreased bacterial spread in tissues, and increased immune cell recruitment and pro-inflammatory cytokine signaling. Together, our findings show how an antiviral mechanism in phagocytes can be exploited by bacterial pathogens, and implicate IFITM3 as a potential antimicrobial therapeutic target.


2021 ◽  
Vol 11 (6) ◽  
pp. 526
Author(s):  
Yejin Lee ◽  
Youn Jung Kim ◽  
Hong-Keun Hyun ◽  
Jae-Cheoun Lee ◽  
Zang Hee Lee ◽  
...  

Hereditary dentin defects can be categorized as a syndromic form predominantly related to osteogenesis imperfecta (OI) or isolated forms without other non-oral phenotypes. Mutations in the gene encoding dentin sialophosphoprotein (DSPP) have been identified to cause dentinogenesis imperfecta (DGI) Types II and III and dentin dysplasia (DD) Type II. While DGI Type I is an OI-related syndromic phenotype caused mostly by monoallelic mutations in the genes encoding collagen type I alpha 1 chain (COL1A1) and collagen type I alpha 2 chain (COL1A2). In this study, we recruited families with non-syndromic dentin defects and performed candidate gene sequencing for DSPP exons and exon/intron boundaries. Three unrelated Korean families were further analyzed by whole-exome sequencing due to the lack of the DSPP mutation, and heterozygous COL1A2 mutations were identified: c.3233G>A, p.(Gly1078Asp) in Family 1 and c.1171G>A, p.(Gly391Ser) in Family 2 and 3. Haplotype analysis revealed different disease alleles in Families 2 and 3, suggesting a mutational hotspot. We suggest expanding the molecular genetic etiology to include COL1A2 for isolated dentin defects in addition to DSPP.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Franziska Eberl ◽  
Thomas Fabisch ◽  
Katrin Luck ◽  
Tobias G. Köllner ◽  
Heiko Vogel ◽  
...  

Abstract Background Protease inhibitors are defense proteins widely distributed in the plant kingdom. By reducing the activity of digestive enzymes in insect guts, they reduce the availability of nutrients and thus impair the growth and development of the attacking herbivore. One well-characterized class of protease inhibitors are Kunitz-type trypsin inhibitors (KTIs), which have been described in various plant species, including Populus spp. Long-lived woody perennials like poplar trees encounter a huge diversity of herbivores, but the specificity of tree defenses towards different herbivore species is hardly studied. We therefore aimed to investigate the induction of KTIs in black poplar (P. nigra) leaves upon herbivory by three different chewing herbivores, Lymantria dispar and Amata mogadorensis caterpillars, and Phratora vulgatissima beetles. Results We identified and generated full-length cDNA sequences of 17 KTIs that are upregulated upon herbivory in black poplar leaves, and analyzed the expression patterns of the eight most up-regulated KTIs via qRT-PCR. We found that beetles elicited higher transcriptional induction of KTIs than caterpillars, and that both caterpillar species induced similar KTI expression levels. Furthermore, KTI expression strongly correlated with the trypsin-inhibiting activity in the herbivore-damaged leaves, but was not dependent on damage severity, i.e. leaf area loss, for most of the genes. Conclusions We conclude that the induction of KTIs in black poplar is controlled at the transcriptional level in a threshold-based manner and is strongly influenced by the species identity of the herbivore. However, the underlying molecular mechanisms and ecological consequences of these patterns remain to be investigated.


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