• 제목/요약/키워드: protein variants

검색결과 153건 처리시간 0.023초

Genetic analysis of the postsynaptic transmembrane X-linked neuroligin 3 gene in autism

  • Hegde, Rajat;Hegde, Smita;Kulkarni, Suyamindra S.;Pandurangi, Aditya;Gai, Pramod B.;Das, Kusal K.
    • Genomics & Informatics
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    • 제19권4호
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    • pp.44.1-44.9
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    • 2021
  • Autism is a complex neurodevelopmental disorder, the prevalence of which has increased drastically in India in recent years. Neuroligin is a type I transmembrane protein that plays a crucial role in synaptogenesis. Alterations in synaptic genes are most commonly implicated in autism and other cognitive disorders. The present study investigated the neuroligin 3 gene in the Indian autistic population by sequencing and in silico pathogenicity prediction of molecular changes. In total, 108 clinically described individuals with autism were included from the North Karnataka region of India, along with 150 age-, sex-, and ethnicity-matched healthy controls. Genomic DNA was extracted from peripheral blood, and exonic regions were sequenced. The functional and structural effects of variants of the neuroligin 3 protein were predicted. One coding sequence variant (a missense variant) and four non-coding variants (two 5'-untranslated region [UTR] variants and two 3'-UTR variants) were recorded. The novel missense variant was found in 25% of the autistic population. The C/C genotype of c.551T>C was significantly more common in autistic children than in controls (p = 0.001), and a significantly increased risk of autism (24.7-fold) was associated with this genotype (p = 0.001). The missense variant showed pathogenic effects and high evolutionary conservation over the functions of the neuroligin 3 protein. In the present study, we reported a novel missense variant, V184A, which causes abnormal neuroligin 3 and was found with high frequency in the Indian autistic population. Therefore, neuroligin is a candidate gene for future molecular investigations and functional analysis in the Indian autistic population.

An Endoplasmic Reticulum Cyclophilin Cpr5p Rescues Z-type α1-Antitrypsin from Retarded Folding

  • Jung, Chan-Hun;Lim, Jeong Hun;Lee, Kyunghee;Im, Hana
    • Bulletin of the Korean Chemical Society
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    • 제35권9호
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    • pp.2781-2786
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    • 2014
  • Human ${\alpha}_1$-antitrypsin (${\alpha}_1$-AT) is a natural inhibitor of neutrophil elastases and has several dozens of genetic variants. Most of the deficient genetic variants of human ${\alpha}_1$-AT are unstable and cause pulmonary emphysema. However, the most clinically significant variant, Z-type ${\alpha}_1$-AT, exhibits retarded protein folding that leads to accumulation of folding intermediates. These aggregate within the endoplasmic reticulum (ER) of hepatocytes, subsequently causing liver cirrhosis as well as emphysema. Here, we studied the role of an ER folding assistant protein Cpr5p on Z-type ${\alpha}_1$-AT folding. Cpr5p was induced > 2-fold in Z-type ${\alpha}_1$-AT-expressing yeast cells compared with the wild type. Knockout of CPR5 exacerbated cytotoxicity of Z-type ${\alpha}_1$-AT, and re-introduction of CPR5 rescued the knockout cells from aggravated cytotoxicity caused by the ${\alpha}_1$-AT variant. Furthermore, Cpr5p co-immunoprecipitated with Z-type ${\alpha}_1$-AT and facilitated its protein folding. Our results suggest that protein-folding diseases may be suppressed by folding assistant proteins at the site of causal protein biosynthesis.

Molecular insights into the role of genetic determinants of congenital hypothyroidism

  • Kollati, Yedukondalu;Akella, Radha Rama Devi;Naushad, Shaik Mohammad;Patel, Rajesh K.;Reddy, G. Bhanuprakash;Dirisala, Vijaya R.
    • Genomics & Informatics
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    • 제19권3호
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    • pp.29.1-29.10
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    • 2021
  • In our previous studies, we have demonstrated the association of certain variants of the thyroid-stimulating hormone receptor (TSHR), thyroid peroxidase (TPO), and thyroglobulin (TG) genes with congenital hypothyroidism. Herein, we explored the mechanistic basis for this association using different in silico tools. The mRNA 3'-untranslated region (3'-UTR) plays key roles in gene expression at the post-transcriptional level. In TSHR variants (rs2268477, rs7144481, and rs17630128), the binding affinity of microRNAs (miRs) (hsa-miR-154-5p, hsa-miR-376a-2-5p, hsa-miR-3935, hsa-miR-4280, and hsa-miR-6858-3p) to the 3'-UTR is disrupted, affecting post-transcriptional gene regulation. TPO and TG are the two key proteins necessary for the biosynthesis of thyroid hormones in the presence of iodide and H2O2. Reduced stability of these proteins leads to aberrant biosynthesis of thyroid hormones. Compared to the wild-type TPO protein, the p.S398T variant was found to exhibit less stability and significant rearrangements of intra-atomic bonds affecting the stoichiometry and substrate binding (binding energies, ΔG of wild-type vs. mutant: -15 vs. -13.8 kcal/mol; and dissociation constant, Kd of wild-type vs. mutant: 7.2E-12 vs. 7.0E-11 M). The missense mutations p.G653D and p.R1999W on the TG protein showed altered ΔG(0.24 kcal/mol and 0.79 kcal/mol, respectively). In conclusion, an in silico analysis of TSHR genetic variants in the 3'-UTR showed that they alter the binding affinities of different miRs. The TPO protein structure and mutant protein complex (p.S398T) are less stable, with potentially deleterious effects. A structural and energy analysis showed that TG mutations (p.G653D and p.R1999W) reduce the stability of the TG protein and affect its structure-functional relationship.

Highly Polymorphic Bovine Leptin Gene

  • Yoon, D.H.;Cho, B.H.;Park, B.L.;Choi, Y.H.;Cheong, H.S.;Lee, H.K.;Chung, E.R.;Cheong, I.C.;Shin, H.D.
    • Asian-Australasian Journal of Animal Sciences
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    • 제18권11호
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    • pp.1548-1551
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    • 2005
  • The leptin, an anti-obesity protein, is a hormone protein expressed and secreted mainly from adipocyte tissue, and involved in regulation of body weight, food intake and energy metabolism. In an effort to discover polymorphism(s) in genes whose variant(s) might be implicated in phenotypic traits of growth, we have sequenced exons and their boundaries of leptin gene including 1,000 bp upstream of promoter region with twenty-four unrelated Korean cattle. Fifty-seven sequence variants were identified: fourteen in 5' flanking region, twenty-seven in introns, eight in exons, and eight in 3' flanking region. By pair-wise linkage analysis among polymorphisms, ten sets of SNPs were in absolute linkage disequilibrium (LD) (|D'| = 1 and $r^2$ = 1). Among variants identified, thirty-six SNPs were newly identified, and twenty-one SNPs, which were reported in other breeds, were also confirmed in Korean cattle. The allele frequencies of variants were quite different among breeds. The information from SNPs of bovine leptin gene could be useful for further genetic studies of this gene.

Genetic Polymorphism of Plasma Vitamin D-Binding Protein (Gc) in Some Asian Sheep

  • Tsunoda, K.;Doge, K.;Hasnath, M.A.;Rajbhandary, H.B.;Xu, W.;Zhanchiv, T.;Chau, B.L.
    • Asian-Australasian Journal of Animal Sciences
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    • 제11권3호
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    • pp.318-322
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    • 1998
  • Using polyacrylamide-gel isoelectric focusing followed by immunoblotting, genetic polymorphism of plasma vitamin D-binding protein (Gc) was examined in Asian sheep. The Gc polymorphism was revealed in the Khalkhas sheep of Mongolia, consisting of F, S and W variants, and the Yunnan native sheep of China, consisting of F and S variants. In particular, W was a new variant. The V variant detected in European sheep up to now was not observed in these sheep. The Bhyanglung, Baruwal, Kagi and Lampuchhre sheep of Nepal and local sheep of Bangladesh and Vietnam were monomorphic for the S variant. Family data and population genetic data supported the hypothesis that these variants were controlled by codominant alleles. In these Asian sheep, distribution of the $Gc^s$ allele was predominant (0.9571-1) and was seen as well in European sheep (Suffolk, Corriedale, Cheviot and Finnish Landrace) raised in Japan. $Gc^w$ allele was detected only in the Khalkhas sheep with the low frequency of 0.0025. The $Gc^v$ allele was detected in the Suffolk and Corriedale sheep (0.0080 and 0.0682), but not in any of the Asian sheep studied.

Structure Based Protein Engineering of Aldehyde Dehydrogenase from Azospirillum brasilense to Enhance Enzyme Activity against Unnatural 3-Hydroxypropionaldehyde

  • Son, Hyeoncheol Francis;Kim, Kyung-Jin
    • Journal of Microbiology and Biotechnology
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    • 제32권2호
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    • pp.170-175
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    • 2022
  • 3-Hydroxypropionic acid (3HP) is a platform chemical and can be converted into other valuable C3-based chemicals. Because a large amount of glycerol is produced as a by-product in the biodiesel industry, glycerol is an attractive carbon source in the biological production of 3HP. Although eight 3HP-producing aldehyde dehydrogenases (ALDHs) have been reported so far, the low conversion rate from 3-hydroxypropionaldehyde (3HPA) to 3HP using these enzymes is still a bottleneck for the production of 3HP. In this study, we elucidated the substrate binding modes of the eight 3HP-producing ALDHs through bioinformatic and structural analysis of these enzymes and selected protein engineering targets for developing enzymes with enhanced enzymatic activity against 3HPA. Among ten AbKGSADH variants we tested, three variants with replacement at the Arg281 site of AbKGSADH showed enhanced enzymatic activities. In particular, the AbKGSADHR281Y variant exhibited improved catalytic efficiency by 2.5-fold compared with the wild type.

Neural Transdifferentiation: MAPTau Gene Expression in Breast Cancer Cells

  • Lara-Padilla, E;Miliar-Garcia, A;Gomez-Lopez, M;Romero-Morelos, P;Bazan-Mendez, CI;Alfaro-Rodriguez, A;Anaya-Ruiz, M;Callender, K;Carlos, A;Bandala, C
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권4호
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    • pp.1967-1971
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    • 2016
  • Background: In tumor cells, aberrant differentiation programs have been described. Several neuronal proteins have been found associated with morphological neuronal-glial changes in breast cancer (BCa). These neuronal proteins have been related to mechanisms that are involved in carcinogenesis; however, this regulation is not well understood. Microtubule-associated protein-tau (MAP-Tau) has been describing in BCa but not its variants. This finding could partly explain the neuronal-glial morphology of BCa cells. Our aim was to determine mRNA expression of MAP-tau variants 2, 4 and 6 in breast cancer cell lines. Materials and Methods: Cultured cell lines MCF-10A, MDA-MB-231, SKBR3 and T47D were observed under phase-contrast microscopy for neural morphology and analyzed for gene expression of MAP-Tau transcript variants 2, 4 and 6 by real-time PCR. Results: Regarding morphology like neural/glial cells, T47D line shown more cells with these features than MDA-MB-231 and SKBR. In another hand, we found much greater mRNA expression of MAP-Tau transcript variants 2, and to a lesser extent 4 and 6, in T47D cells than the other lines. In conclusion, regulation of MAP-Tau could bring about changes in cytoskeleton, cell morphology and motility; these findings cast further light on neuronal transdifferentiation in BCa.

Transcriptional regulation of genetic variants in the SLC40A1 promoter

  • Seung Yeon Ha;Jin-Young Kim;Ji Ha Choi
    • The Korean Journal of Physiology and Pharmacology
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    • 제28권2호
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    • pp.113-120
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    • 2024
  • Solute carrier 40A1 (SLC40A1) encodes ferroportin, which is the only known transmembrane protein that exports elemental iron from mammalian cells and is essential for iron homeostasis. Mutations in SLC40A1 are associated with iron-overload disorders. In addition to ferroportin diseases, SLC40A1 expression is downregulated in various cancer types. Despite the clinical significance of the SLC40A1 transporter, only a few studies have investigated genetic variants in SLC40A1. The present study was performed to identify genetic variations in the SLC40A1 promoter and functionally characterize each variant using in vitro assays. We investigated four haplotypes and five variants in the SLC40A1 promoter. We observed that haplotype 3 (H3) had significantly lower promoter activity than H1, whereas the activity of H4 was significantly higher than that of H1. Luciferase activity of H2 was comparable to that of H1. In addition, four variants of SLC40A1, c.-1355G>C, c.-662C>T, c.-98G>C, and c.-8C>G, showed significantly increased luciferase activity compared to the wild type (WT), whereas c.-750G>A showed significantly decreased luciferase activity compared to the WT. Three transcription factors, cAMP response element-binding protein-1 (CREB-1), chicken ovalbumin upstream promoter transcription factor 1, and hepatic leukemia factor (HLF), were predicted to bind to the promoter regions of SLC40A1 near c.-662C>T, c.-98G>C, and c.-8C>G, respectively. Among these, CREB1 and HLF bound more strongly to the variant sequences than to the WT and functioned as activators of SLC40A1 transcription. Collectively, our findings indicate that the two SLC40A1 promoter haplotypes affect SLC40A1 transcription, which is regulated by CREB-1 and HLF.

Multi-omics techniques for the genetic and epigenetic analysis of rare diseases

  • Yeonsong Choi;David Whee-Young Choi;Semin Lee
    • Journal of Genetic Medicine
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    • 제20권1호
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    • pp.1-5
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    • 2023
  • Until now, rare disease studies have mainly been carried out by detecting simple variants such as single nucleotide substitutions and short insertions and deletions in protein-coding regions of disease-associated gene panels using diagnostic next-generation sequencing in association with patient phenotypes. However, several recent studies reported that the detection rate hardly exceeds 50% even when whole-exome sequencing is applied. Therefore, the necessity of introducing whole-genome sequencing is emerging to discover more diverse genomic variants and examine their association with rare diseases. When no diagnosis is provided by whole-genome sequencing, additional omics techniques such as RNA-seq also can be considered to further interrogate causal variants. This paper will introduce a description of these multi-omics techniques and their applications in rare disease studies.

The Relationship between Milk Protein Phenotypes and Lactation Traits in Brown Swiss and Canadienne

  • Kim, S.;Ng-Kwai-Hang, K.F.;Hayes, J.F.
    • Asian-Australasian Journal of Animal Sciences
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    • 제11권3호
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    • pp.311-317
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    • 1998
  • A total of 1033 Brown Swiss and 610 Canadienne cows were phenotyped for the genetic variants ${\alpha}_{s1}$-casein, ${\beta}$-casein, ${\kappa}$-casein, ${\beta}$-lactoglobulin and ${\alpha}$-lactalbumin. In Brown Swiss, frequency distributions were: 97.3% B and 2.7% C variant of ${\alpha}_{s1}$-casein; 31.6% $A^1$, 51.8% $A^2$, 0.5% $A^3$ and 16.1% B variant of ${\beta}$-casein; 70.4% A, 29.3% B, and 0.3% C variant of ${\kappa}$-casein; 41.7% A and 58.3% B variant of ${\beta}$-lactoglobulin; and 100% B variant of ${\alpha}$-lactalbumin. Corresponding frequencies in Canadienne for those five milk proteins were: 98.6 and 1.4%;58.5, 33.5, 0.08 and 7.9%; 78.8, 21.1 and 0.1%, 42.4 and 57.6%; and 100%. Analysis of variance by least squares showed possible association between milk protein phenotypes and some lactational production traits. There were no significant association of phenotypes of ${\alpha}_{s1}$-casein, ${\beta}$-casein and ${\beta}$-lactoglobulin with milk yield, fat yield, protein yield, fat percentage and protein percentage in both breeds during the three lactations. In the Brown Swiss, ${\kappa}$-casein phenotype was associated with 305-day fat yield and protein yield during the first lactation. ${\kappa}$-Casein AB was associated with higher milk, fat and protein yield during the second lactation. During the third lactation, ${\beta}$-lactoglobulin AA in Canadienne cows was associated with higher protein content in the milk (3.70%) when compared to phenotypes AB (3.54%) and BB (3.64%).