scholarly journals Characterization of Coding/Noncoding Variants for SHROOM3 in Patients with CKD

2018 ◽  
Vol 29 (5) ◽  
pp. 1525-1535 ◽  
Author(s):  
Jeremy W. Prokop ◽  
Nan Cher Yeo ◽  
Christian Ottmann ◽  
Surya B. Chhetri ◽  
Kacie L. Florus ◽  
...  

Background Interpreting genetic variants is one of the greatest challenges impeding analysis of rapidly increasing volumes of genomic data from patients. For example, SHROOM3 is an associated risk gene for CKD, yet causative mechanism(s) of SHROOM3 allele(s) are unknown.Methods We used our analytic pipeline that integrates genetic, computational, biochemical, CRISPR/Cas9 editing, molecular, and physiologic data to characterize coding and noncoding variants to study the human SHROOM3 risk locus for CKD.Results We identified a novel SHROOM3 transcriptional start site, which results in a shorter isoform lacking the PDZ domain and is regulated by a common noncoding sequence variant associated with CKD (rs17319721, allele frequency: 0.35). This variant disrupted allele binding to the transcription factor TCF7L2 in podocyte cell nuclear extracts and altered transcription levels of SHROOM3 in cultured cells, potentially through the loss of repressive looping between rs17319721 and the novel start site. Although common variant mechanisms are of high utility, sequencing is beginning to identify rare variants involved in disease; therefore, we used our biophysical tools to analyze an average of 112,849 individual human genome sequences for rare SHROOM3 missense variants, revealing 35 high-effect variants. The high-effect alleles include a coding variant (P1244L) previously associated with CKD (P=0.01, odds ratio=7.95; 95% CI, 1.53 to 41.46) that we find to be present in East Asian individuals at an allele frequency of 0.0027. We determined that P1244L attenuates the interaction of SHROOM3 with 14–3-3, suggesting alterations to the Hippo pathway, a known mediator of CKD.Conclusions These data demonstrate multiple new SHROOM3-dependent genetic/molecular mechanisms that likely affect CKD.

Blood ◽  
2006 ◽  
Vol 107 (6) ◽  
pp. 2322-2329 ◽  
Author(s):  
Mary Yanxia Liu ◽  
Melanie Eyries ◽  
Chunyan Zhang ◽  
Fernando S. Santiago ◽  
Levon M. Khachigian

AbstractPlatelet-derived growth factor D-chain (PDGF-D) is the newest member of the PDGF family of mitogens and chemoattractants expressed in a wide variety of cell types, including vascular smooth muscle cells (SMCs). The molecular mechanisms regulating PDGF-D transcription are not known. Primer extension analysis mapped a single transcriptional start site to the ccAGCGC motif with several potential Ets motifs located upstream. Ets-1, but not Ets-1 bearing only the DNA-binding domain, activates the PDGF-D promoter and mRNA expression in SMCs. Ets site D3 (–470GGAT–467) is singly required for basal and Ets-1–inducible PDGF-D promoter-dependent expression. D3 supports the interaction of endogenous and recombinant Ets-1 and Sp1. Sp1, like Ets-1, induces PDGF-D transcription and mRNA expression, which is blocked by mutant Ets-1. H2O2 stimulates Ets-1, but not Sp1, and activates D3-dependent PDGF-D transcription. Ets-1 and Sp1 siRNA block peroxide-inducible PDGF-D expression. Angiotensin II (ATII) induction of PDGF-D and Ets-1 was blocked by prior incubation of the cells with PEG-catalase, but not BSA, indicating that ATII-inducible Ets-1 and PDGF-D expression is mediated via H2O2. Thus, 2 separate trans-acting factors regulate PDGF-D transcription, alone and in response to oxidative stress.


1993 ◽  
Vol 13 (8) ◽  
pp. 4894-4903 ◽  
Author(s):  
Y Geng ◽  
L F Johnson

The mouse thymidylate synthase promoter lacks a TATA box and initiates transcription at many sites across a 90-nucleotide initiation window. We showed previously that wild-type promoter activity is maintained with a promoter that extends only 13 nucleotides upstream of the first start site. G/A-rich and G/C-rich promoter elements were identified in the vicinity of the first transcriptional start site. The goals of the present study were to determine whether there are additional promoter elements in the initiation window and to determine why transcription initiates across such a broad region. Minigenes containing a variety of substitution, deletion, and insertion mutations in the promoter region were transfected into cultured cells, and the effects on expression and the pattern of start sites were determined. The results indicate that there are no additional promoter elements downstream of the G/C box. The boundaries of the transcription window are established by elements near the 5' end of the window, whereas the pattern of start sites is determined by sequences within the window. The promoter lacks an initiator element. When an initiator element was inserted, transcription initiated predominantly at the position directed by the initiator when it was inserted within the initiation window but not when it was inserted immediately upstream of the window.


1993 ◽  
Vol 13 (8) ◽  
pp. 4894-4903
Author(s):  
Y Geng ◽  
L F Johnson

The mouse thymidylate synthase promoter lacks a TATA box and initiates transcription at many sites across a 90-nucleotide initiation window. We showed previously that wild-type promoter activity is maintained with a promoter that extends only 13 nucleotides upstream of the first start site. G/A-rich and G/C-rich promoter elements were identified in the vicinity of the first transcriptional start site. The goals of the present study were to determine whether there are additional promoter elements in the initiation window and to determine why transcription initiates across such a broad region. Minigenes containing a variety of substitution, deletion, and insertion mutations in the promoter region were transfected into cultured cells, and the effects on expression and the pattern of start sites were determined. The results indicate that there are no additional promoter elements downstream of the G/C box. The boundaries of the transcription window are established by elements near the 5' end of the window, whereas the pattern of start sites is determined by sequences within the window. The promoter lacks an initiator element. When an initiator element was inserted, transcription initiated predominantly at the position directed by the initiator when it was inserted within the initiation window but not when it was inserted immediately upstream of the window.


2018 ◽  
Author(s):  
Stacy A. Malaker ◽  
Kayvon Pedram ◽  
Michael J. Ferracane ◽  
Elliot C. Woods ◽  
Jessica Kramer ◽  
...  

<div> <div> <div> <p>Mucins are a class of highly O-glycosylated proteins that are ubiquitously expressed on cellular surfaces and are important for human health, especially in the context of carcinomas. However, the molecular mechanisms by which aberrant mucin structures lead to tumor progression and immune evasion have been slow to come to light, in part because methods for selective mucin degradation are lacking. Here we employ high resolution mass spectrometry, polymer synthesis, and computational peptide docking to demonstrate that a bacterial protease, called StcE, cleaves mucin domains by recognizing a discrete peptide-, glycan-, and secondary structure- based motif. We exploited StcE’s unique properties to map glycosylation sites and structures of purified and recombinant human mucins by mass spectrometry. As well, we found that StcE will digest cancer-associated mucins from cultured cells and from ovarian cancer patient-derived ascites fluid. Finally, using StcE we discovered that Siglec-7, a glyco-immune checkpoint receptor, specifically binds sialomucins as biological ligands, whereas the related Siglec-9 receptor does not. Mucin-specific proteolysis, as exemplified by StcE, is therefore a powerful tool for the study of glycoprotein structure and function and for deorphanizing mucin-binding receptors. </p> </div> </div> </div>


1991 ◽  
Vol 11 (2) ◽  
pp. 1023-1029
Author(s):  
Y Li ◽  
D Li ◽  
K Osborn ◽  
L F Johnson

The thymidylate synthase (TS) gene is a housekeeping gene that is expressed at much higher levels in proliferating cells than in quiescent cells. We have studied the role of the TS 5'-flanking sequences in regulating the level of expression of the mouse TS gene. A variety of chimeric TS minigenes that contain different promoters linked either to the TS coding region (with or without introns) or to the chloramphenicol acetyltransferase (CAT) coding region were constructed. The activities of the minigenes were determined by transfecting them into cultured cells and measuring the levels of mRNA or enzyme derived from the chimeric genes. We found that the mouse TS promoter had about the same strength as the simian virus 40 early promoter but was significantly stronger than the herpes simplex virus thymidine kinase promoter. Stable transfection studies revealed that minigenes consisting of the normal TS promoter (extending to -1 kb), coding region, and polyadenylation signal were regulated normally in response to growth stimulation. When the TS promoter was replaced by the simian virus 40 early promoter or by a TS promoter that retained only 60 nucleotides upstream of the first transcriptional start site, the minigene was expressed constitutively. A minigene consisting of the TS promoter (extending to -1 kb) linked to the CAT coding region was also expressed constitutively. These observations indicate that sequences upstream of the transcriptional start sites of the TS gene are necessary, although not sufficient, for normal growth-regulated expression of the mouse TS gene.


Author(s):  
Kanchana Suksri ◽  
Namoiy Semprasert ◽  
Mutita Junking ◽  
Suchanoot Kutpruek ◽  
Thawornchai Limjindaporn ◽  
...  

Long-term medication with dexamethasone (a synthetic glucocorticoid (GC) drug) results in hyperglycemia, or steroid-induced diabetes. Although recent studies revealed dexamethasone directly induces pancreatic β-cell apoptosis, its molecular mechanisms remain unclear. In our initial analysis of mRNA transcripts, we discovered the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) pathway may be involved in dexamethasone-induced pancreatic β-cell apoptosis. In the present study, a mechanism of dexamethasone-induced pancreatic β-cell apoptosis through the TRAIL pathway was investigated in cultured cells and isolated mouse islets. INS-1 cells were cultured with and without dexamethasone in the presence or absence of a glucocorticoid receptor (GR) inhibitor, RU486. We found that dexamethasone induced pancreatic β-cell apoptosis in association with the upregulation of TRAIL mRNA and protein expression. Moreover, dexamethasone upregulated the TRAIL death receptor (DR5) protein but suppressed the decoy receptor (DcR1) protein. Similar findings were observed in mouse isolated islets: dexamethasone increased TRAIL and DR5 compared to that of control mice. Furthermore, dexamethasone stimulated pro-apoptotic signaling including superoxide production, caspase-8, -9, and -3 activities, NF-B, and Bax, but repressed the anti-apoptotic protein, Bcl-2. All these effects were inhibited by the GR-inhibitor, RU486. Furthermore, knock down DR5 decreased dexamethasone-induced caspase 3 activity. Caspase-8 and caspase-9 inhibitors protected pancreatic β-cells from dexamethasone-induced apoptosis. Taken together, dexamethasone induced pancreatic β-cell apoptosis by binding to the GR and inducing DR5 and TRAIL pathway.


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Nicolas Maillard ◽  
Veronique Fremeaux Bacchi ◽  
Paula Vieira-Martins ◽  
Perrine Jullien ◽  
Eric Alamartine ◽  
...  

Abstract Background and Aims IgA nephropathy is the most frequent primary glomerulonephritis leading to end stage renal disease (ESRD) in about 30% of cases within 20 years after diagnosis. Complement activation through alternative and lectin pathways has been described to impact the pathogeny of the disease. We hypothesized in this study that rare variants of alternative pathways regulatory genes could be overrepresented and could play a role at initiating the disease and could harm the prognosis of IgA Nephropathy. Method Patients with biopsy proven IgA nephropathy with markers of severity comprising an evolution through ESRD and/or a proteinuria &gt;0.5g/day with available DNA sample were included. All coding sequences of CFH, CFI, MCP, C3, Factor B THBD and CFHR5 genes were analyzed by next generation sequencing. We defined a variant as rare when its minor allele frequency was below 0.1% in the general population. Frequencies were compared to a French volonteers cohort (n=80) and a European large cohort (n=503) Results We screened 128 patients with IgA N, with following characteristics at diagnosis: median age 42.4 yo, proteinuria (median) 1.4g/day, hypertension 66%, median eGFR 48.7 mL/min/1.73m². The median follow-up was 99 months and 58% of patients progressed to ESRD. We identified rare variants with MAF&lt;0.1% in 10.2 % (n=13) including 1 patient with two rare variants. The functional consequences of the 12 out the 14 variants are unknown. Two variants in CFH are located in function domains and are pathogenic. Patients with IgA N have high rates of rare variants in CFH (n=9/128 ; 7 %) versus normal controls (n=9/503 ; 1.8%) (p=0.004); Pathogenic Variants with minor allele frequency &lt;0.1% in CFH were found in 2 IgA N (2 out of 128, 1.5%) versus 1 European controls (1 out of 503) In total, 11 % (14/128), 3.8 % (5/128) and 0.8 % (1/128) of the 128 patients were homozygous for the at-risk haplotype MCP ggaac, CFH tgtgt or both, respectively (versus 6.2 % (5/80), 3.8 % (3/80) and 0% in the controls) 6 patients carried the pathogenic variant in THDM gene p.Ala43Thr (6/128) versus 5 in 508 controls population (p=0.01). No difference in term of hypertension, proteinuria, eGFR, Oxford classification, vascular score at diagnosis was noticed between patients without any rare variant compared to patients with at least one rare variant. The progression through ESRD was not different between groups. Conclusion In this cohort of Caucasian IgA nephropathy patients, rare variants of CFH and THBD were found significantly overrepresented compared to a French and European control cohort. Rare variants of alternative pathway regulatory genes were not associated with particular severity or prognosis.


2000 ◽  
Vol 3 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Q. XIE ◽  
D. H. ALPERS

Xie, Q., and D. H. Alpers. The two isozymes of rat intestinal alkaline phosphatase are products of two distinct genes. Physiol Genomics 3: 1–8, 2000.—Rat intestinal alkaline phosphatases (IAP-I and -II) differ in primary structure, substrate specificity, tissue localization, and response to fat feeding. This study identifies two distinct genes (∼5–6 kb) corresponding to each isozyme and containing 11 exons of nearly identical size. The exon-intron junctions are identical with those found in IAP genes from other species. The 1.7 and 1.2 bp of 5′ flanking regions isolated from each gene, respectively, contain Sp1 and gut-enriched Kruppel-like factor (GKLF) binding sites, but otherwise show little identity. There is a potential CAAT-box 14 bp 5′ to the transcriptional start site, 36 bp upstream from IAP-I, and a TATA-box 31 bp 5′ to the transcriptional start site, 55 bp upstream from IAP-II. Transfection of these promoter regions (linked to luciferase as a reporter gene) into a kidney cell line, COS-7, produced the differential response to oleic acid expected from in vivo studies, i.e., threefold increase using the 5′ flanking region of IAP-II, but not IAP-I. This response was not reproduced by 5,8,11,14-eicosatetraynoic acid (ETYA) or clofibrate, suggesting that peroxisome proliferator response elements are not involved. Isolation of the IAP-II gene will allow determination of the sequences responsible for dietary fat response in the enterocyte.


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