Three tightly linked genes encoding human type I keratins: conservation of sequence in the 5'-untranslated leader and 5'-upstream regions of coexpressed keratin genes.

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.

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Non-Syndromic Dentinogenesis Imperfecta Caused by Mild Mutations in COL1A2

Journal of Personalized Medicine ◽

10.3390/jpm11060526 ◽

2021 ◽

Vol 11 (6) ◽

pp. 526

Author(s):

Yejin Lee ◽

Youn Jung Kim ◽

Hong-Keun Hyun ◽

Jae-Cheoun Lee ◽

Zang Hee Lee ◽

...

Keyword(s):

Collagen Type ◽

Molecular Genetic ◽

Collagen Type I ◽

Type I ◽

Dentinogenesis Imperfecta ◽

Gene Encoding ◽

Korean Families ◽

Whole Exome ◽

Genes Encoding ◽

Candidate Gene Sequencing

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.

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Biochemical and Mutational Analysis of Glutamine Synthetase Type III from the Rumen Anaerobe Ruminococcus albus 8

Journal of Bacteriology ◽

10.1128/jb.187.21.7481-7491.2005 ◽

2005 ◽

Vol 187 (21) ◽

pp. 7481-7491 ◽

Cited By ~ 21

Author(s):

Kensey R. Amaya ◽

Svetlana A. Kocherginskaya ◽

Roderick I. Mackie ◽

Isaac K. O. Cann

Keyword(s):

Glutamine Synthetase ◽

Mutational Analysis ◽

Sufficient Conditions ◽

Kinetic Studies ◽

Type I ◽

Gene Encoding ◽

Genes Encoding ◽

Subunit Organization ◽

Glutamyl Transferase ◽

First Time

ABSTRACT Two different genes encoding glutamine synthetase type I (GSI) and GSIII were identified in the genome sequence of R. albus 8. The identity of the GSIII protein was confirmed by the presence of its associated conserved motifs. The glnN gene, encoding the GSIII, was cloned and expressed in Escherichia coli BL21 cells. The recombinant protein was purified and subjected to biochemical and physical analyses. Subunit organization suggested a protein present in solution as both monomers and oligomers. Kinetic studies using the forward and the γ-glutamyl transferase (γ-GT) assays were carried out. Mutations that changed conserved glutamic acid residues to alanine in the four GSIII motifs resulted in drastic decreases in GS activity using both assays, except for an E380A mutation, which rather resulted in an increase in activity in the forward assay compared to the wild-type protein. Reduced GSIII activity was also exhibited by mutating, individually, two lysines (K308 and K318) located in the putative nucleotide-binding site to alanine. Most importantly, the presence of mRNA transcripts of the glnN gene in R. albus 8 cells grown under ammonia limiting conditions, whereas little or no transcript was detected in cells grown under ammonia sufficient conditions, suggested an important role for the GSIII in the nitrogen metabolism of R. albus 8. Furthermore, the mutational studies on the conserved GSIII motifs demonstrated, for the first time, their importance in the structure and/or function of a GSIII protein.

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Sequence and expression of a type II keratin, K5, in human epidermal cells

Molecular and Cellular Biology ◽

10.1128/mcb.8.1.486-493.1988 ◽

1988 ◽

Vol 8 (1) ◽

pp. 486-493

Author(s):

R Lersch ◽

E Fuchs

Keyword(s):

Human Gene ◽

Basal Layer ◽

Epidermal Cells ◽

Amino Acid Sequences ◽

Type I ◽

Type Ii ◽

Gene Encoding ◽

Human Epidermal Cells ◽

Rna Blot Analysis

We report here the cDNA and amino acid sequences of a human 58-kilodalton type II keratin, K5, which is coexpressed with a 50-kilodalton type I keratin partner, K14, in stratified squamous epithelia. Using a probe specific for the 3'-noncoding portion of this K5 cDNA, we demonstrated the existence of a single human gene encoding this sequence. Using Northern (RNA) blot analysis and in situ hybridization with cRNA probes for both K5 and K14, we examined the expression of these mRNAs in the epidermis and in cultured epidermal cells. Our results indicate that the mRNAs for K5 and K14 are coordinately expressed and abundant in the basal layer of the epidermis. As cells undergo a commitment to terminally differentiate, the expression of both mRNAs seems to be downregulated.

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Sequence and expression of a type II keratin, K5, in human epidermal cells.

Molecular and Cellular Biology ◽

10.1128/mcb.8.1.486 ◽

1988 ◽

Vol 8 (1) ◽

pp. 486-493 ◽

Cited By ~ 49

Author(s):

R Lersch ◽

E Fuchs

Keyword(s):

Human Gene ◽

Basal Layer ◽

Epidermal Cells ◽

Amino Acid Sequences ◽

Type I ◽

Type Ii ◽

Gene Encoding ◽

Human Epidermal Cells ◽

Rna Blot Analysis

We report here the cDNA and amino acid sequences of a human 58-kilodalton type II keratin, K5, which is coexpressed with a 50-kilodalton type I keratin partner, K14, in stratified squamous epithelia. Using a probe specific for the 3'-noncoding portion of this K5 cDNA, we demonstrated the existence of a single human gene encoding this sequence. Using Northern (RNA) blot analysis and in situ hybridization with cRNA probes for both K5 and K14, we examined the expression of these mRNAs in the epidermis and in cultured epidermal cells. Our results indicate that the mRNAs for K5 and K14 are coordinately expressed and abundant in the basal layer of the epidermis. As cells undergo a commitment to terminally differentiate, the expression of both mRNAs seems to be downregulated.

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

Molecular and Cellular Biology ◽

10.1128/mcb.9.9.3685-3697.1989 ◽

1989 ◽

Vol 9 (9) ◽

pp. 3685-3697

Author(s):

R Lersch ◽

V Stellmach ◽

C Stocks ◽

G Giudice ◽

E Fuchs

Keyword(s):

Molecular Mechanisms ◽

Gene Transfection ◽

Epidermal Differentiation ◽

Foreign Gene ◽

Transcriptional Level ◽

Type I ◽

Multiple Control ◽

Gene Encoding ◽

Subsequent Formation ◽

Squamous Epithelia

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.

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Hereditary Dentin Defects

Journal of Dental Research ◽

10.1177/154405910708600502 ◽

2007 ◽

Vol 86 (5) ◽

pp. 392-399 ◽

Cited By ~ 147

Author(s):

J.-W. Kim ◽

J.P. Simmer

Keyword(s):

Matrix Protein ◽

Type I Collagen ◽

Rare Condition ◽

Type I ◽

Gene Encoding ◽

Apparent Lack ◽

Post Translational Modifications ◽

Dentin Matrix Protein ◽

Genes Encoding ◽

Secreted Phosphoprotein 1

By the Shields classification, articulated over 30 years ago, inherited dentin defects are divided into 5 types: 3 types of dentinogenesis imperfecta (DGI), and 2 types of dentin dysplasia (DD). DGI type I is osteogenesis imperfecta (OI) with DGI. OI with DGI is caused, in most cases, by mutations in the 2 genes encoding type I collagen. Many genes are required to generate the enzymes that catalyze collagen’s diverse post-translational modifications and its assembly into fibers, fibrils, bundles, and networks. Rare inherited diseases of bone are caused by defects in these genes, and some are occasionally found to include DGI as a feature. Appreciation of the complicated genetic etiology of DGI associated with bony defects splintered the DGI type I description into a multitude of more precisely defined entities, all with their own designations. In contrast, DD-II, DGI-II, and DGI-III, each with its own pattern of inherited defects limited to the dentition, have been found to be caused by various defects in DSPP (dentin sialophosphoprotein), a gene encoding the major non-collagenous proteins of dentin. Only DD-I, an exceedingly rare condition featuring short, blunt roots with obliterated pulp chambers, remains untouched by the revolution in genetics, and its etiology is still a mystery. A major surprise in the characterization of genes underlying inherited dentin defects is the apparent lack of roles played by the genes encoding the less-abundant non-collagenous proteins in dentin, such as dentin matrix protein 1 ( DMP1), integrin-binding sialoprotein ( IBSP), matrix extracellular phosphoglycoprotein ( MEPE), and secreted phosphoprotein-1, or osteopontin ( SPP1, OPN). This review discusses the development of the dentin extracellular matrix in the context of its evolution, and discusses the phenotypes and clinical classifications of isolated hereditary defects of tooth dentin in the context of recent genetic data respecting their genetic etiologies.

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Thrombocytosis in children and adolescents—classification, diagnostic approach, and clinical management

Annals of Hematology ◽

10.1007/s00277-021-04485-0 ◽

2021 ◽

Author(s):

Clemens Stockklausner ◽

◽

C. M. Duffert ◽

H. Cario ◽

R. Knöfler ◽

...

Keyword(s):

Clinical Management ◽

Molecular Mechanisms ◽

Myeloproliferative Neoplasms ◽

Pediatric Population ◽

Primary Myelofibrosis ◽

Driver Mutations ◽

Gene Encoding ◽

Clinical Complications ◽

Genes Encoding ◽

Infection And Inflammation

AbstractSecondary thrombocytosis is a frequent secondary finding in childhood infection and inflammation. Primary hereditary thrombocytosis may be caused by germline mutations within the genes encoding key regulators of thrombopoiesis, i.e., thrombopoietin (THPO) and its receptor c-MPL (MPL) or the receptor’s effector kinase Januskinase2 (JAK2). Furthermore, somatic mutations in JAK2, MPL, and in the gene-encoding calreticulin (CALR) have been described to act as driver mutations within the so-called Philadelphia-negative myeloproliferative neoplasms (MPNs), namely essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (PMF). Increasing knowledge on the molecular mechanisms and on the clinical complications of these diseases is reflected by the WHO diagnostic criteria and European LeukemiaNet (ELN) recommendations on the management of adult MPN. However, data on childhood thrombocytosis are rare, and no consensus guidelines for pediatric thrombocytosis exist. Current literature has highlighted differences in the epidemiology and molecular pathogenesis of childhood thrombocytosis as compared to adults. Furthermore, age-dependent complications and pharmacological specificities suggest that recommendations tailored to the pediatric population are necessary in clinical practice. Here we summarize literature on classification, diagnostics, and clinical management of childhood thrombocytosis.

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

Molecular and Cellular Biology ◽

10.1128/mcb.9.9.3685 ◽

1989 ◽

Vol 9 (9) ◽

pp. 3685-3697 ◽

Cited By ~ 56

Author(s):

R Lersch ◽

V Stellmach ◽

C Stocks ◽

G Giudice ◽

E Fuchs

Keyword(s):

Molecular Mechanisms ◽

Gene Transfection ◽

Epidermal Differentiation ◽

Foreign Gene ◽

Transcriptional Level ◽

Type I ◽

Multiple Control ◽

Gene Encoding ◽

Subsequent Formation ◽

Squamous Epithelia

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.

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The apelin/APJ system in the regulation of vascular tone: friend or foe?

The Journal of Biochemistry ◽

10.1093/jb/mvaa129 ◽

2020 ◽

Author(s):

Yoshiyuki Rikitake

Keyword(s):

Smooth Muscle ◽

Vascular Tone ◽

Molecular Mechanisms ◽

Pathological Condition ◽

Critical Role ◽

Cell Types ◽

Peptide Ligands ◽

Type I ◽

Gene Encoding ◽

Regulation Of Vascular Tone

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.

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