| 1. |
- Huffman, Jennifer E., et al.
(författare)
-
Polymorphisms in B3GAT1, SLC9A9 and MGAT5 are associated with variation within the human plasma N-glycome of 3533 European adults
- 2011
-
Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 20:24, s. 5000-5011
-
Tidskriftsartikel (refereegranskat)abstract
- The majority of human proteins are post-translationally modified by covalent addition of one or more complex oligosaccharides (glycans). Alterations in glycosylation processing are associated with numerous diseases and glycans are attracting increasing attention both as disease biomarkers and as targets for novel therapeutic approaches. Using a recently developed high-throughput high-performance liquid chromatography (HPLC) analysis method, we have reported, in a pilot genome-wide association study of 13 glycan features in 2705 individuals from three European populations, that polymorphisms at three loci (FUT8, FUT6/FUT3 and HNF1A) affect plasma levels of N-glycans. Here, we extended the analysis to 33 directly measured and 13 derived glycosylation traits in 3533 individuals and identified three novel gene association (MGAT5, B3GAT1 and SLC9A9) as well as replicated the previous findings using an additional European cohort. MGAT5 (meta-analysis association P-value = 1.80 x 10(-10) for rs1257220) encodes a glycosyltransferase which is known to synthesize the associated glycans. In contrast, neither B3GAT1 (rs7928758, P = 1.66 x 10(-08)) nor SLC9A9 (rs4839604, P = 3.50 x 10(-13)) had previously been associated functionally with glycosylation of plasma proteins. Given the glucuronyl transferase activity of B3GAT1, we were able to show that glucuronic acid is present on antennae of plasma glycoproteins underlying the corresponding HPLC peak. SLC9A9 encodes a proton pump which affects pH in the endosomal compartment and it was recently reported that changes in Golgi pH can impair protein sialylation, giving a possible mechanism for the observed association.
|
|
| 2. |
- Lauc, Gordan, et al.
(författare)
-
Genomics Meets Glycomics-The First GWAS Study of Human N-Glycome Identifies HNF1 alpha as a Master Regulator of Plasma Protein Fucosylation
- 2010
-
Ingår i: PLoS Genetics. - : Public Library of Science (PLoS). - 1553-7390 .- 1553-7404. ; 6:12, s. e1001256-
-
Tidskriftsartikel (refereegranskat)abstract
- Over half of all proteins are glycosylated, and alterations in glycosylation have been observed in numerous physiological and pathological processes. Attached glycans significantly affect protein function; but, contrary to polypeptides, they are not directly encoded by genes, and the complex processes that regulate their assembly are poorly understood. A novel approach combining genome-wide association and high-throughput glycomics analysis of 2,705 individuals in three population cohorts showed that common variants in the Hepatocyte Nuclear Factor 1 alpha (HNF1 alpha) and fucosyltransferase genes FUT6 and FUT8 influence N-glycan levels in human plasma. We show that HNF1 alpha and its downstream target HNF4 alpha regulate the expression of key fucosyltransferase and fucose biosynthesis genes. Moreover, we show that HNF1 alpha is both necessary and sufficient to drive the expression of these genes in hepatic cells. These results reveal a new role for HNF1 alpha as a master transcriptional regulator of multiple stages in the fucosylation process. This mechanism has implications for the regulation of immunity, embryonic development, and protein folding, as well as for our understanding of the molecular mechanisms underlying cancer, coronary heart disease, and metabolic and inflammatory disorders.
|
|
| 3. |
- Pivac, Nela, et al.
(författare)
-
Human Plasma Glycome in Attention-Deficit Hyperactivity Disorder and Autism Spectrum Disorders
- 2011
-
Ingår i: Molecular & Cellular Proteomics. - 1535-9476 .- 1535-9484. ; 10:1
-
Tidskriftsartikel (refereegranskat)abstract
- Over a half of all proteins are glycosylated, and their proper glycosylation is essential for normal function. Unfortunately, because of structural complexity of nonlinear branched glycans and the absence of genetic template for their synthesis, the knowledge about glycans is lagging significantly behind the knowledge about proteins or DNA. Using a recently developed quantitative high throughput glycan analysis method we quantified components of the plasma N-glycome in 99 children with attention-deficit hyperactivity disorder (ADHD), 81 child and 5 adults with autism spectrum disorder, and a total of 340 matching healthy controls. No changes in plasma glycome were found to associate with autism spectrum disorder, but several highly significant associations were observed with ADHD. Further structural analysis of plasma glycans revealed that ADHD is associated with increased antennary fucosylation of biantennary glycans and decreased levels of some complex glycans with three or four antennas. The design of this study prevented any functional conclusions about the observed associations, but specific differences in glycosylation appears to be strongly associated with ADHD and warrants further studies in this direction.
|
|
| 4. |
- Thanabalasingham, Gaya, et al.
(författare)
-
Mutations in HNF1A Result in Marked Alterations of Plasma Glycan Profile
- 2013
-
Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 62:4, s. 1329-1337
-
Tidskriftsartikel (refereegranskat)abstract
- A recent genome-wide association study identified hepatocyte nuclear factor 1-alpha (HNF1A) as a key regulator of fucosylation. We hypothesized that loss-of-function HNF1A mutations causal for maturity-onset diabetes of the young (MOD?) would display altered fucosylation of N-linked glycans on plasma proteins and that glycan biomarkers could improve the efficiency of a diagnosis of HNF1A-MODY. In a pilot comparison of 33 subjects with HNF1A-MODY and 41 subjects with type 2 diabetes, 15 of 29 glycan measurements differed between the two groups. The DG9-glycan index, which is the ratio of fucosylated to nonfucosylated triantennary glycans, provided optimum discrimination in the pilot study and was examined further among additional subjects with HNF1A-MODY (n = 188), glucokinase (GCE)-MODY (n = 118), hepatocyte nuclear factor 4-alpha (HNF4A)-MODY (n = 40), type 1 diabetes (n = 98), type 2 diabetes (n = 167), and nondiabetic controls (n = 98). The DG9-glycan index was markedly lower in HNF1A-MODY than in controls or other diabetes subtypes, offered good discrimination between HNF1A-MODY and both type 1 and type 2 diabetes (C statistic >= 0.90), and enabled us to detect three previously undetected HNF1A mutations in patients with diabetes. In conclusion, glycan profiles are altered substantially in HNF1A-MODY, and the DG9-glycan index has potential clinical value as a diagnostic biomarker of HNF1A dysfunction.
|
|
