|
|
Identification of basolateral localization motifs of the urate transporter GLUT9 using functional studies.
Pácalová, Eliška ; Krylov, Vladimír (advisor) ; Pavelcová, Kateřina (referee)
The GLUT9 transporter, coded by the SLC2A9 gene, is one of the key proteins enabling the trasnfer of uric acid across the membrane in epithelial cells of the proximal tubule. In humans, this protein is naturally expressed in two variants: long (GLUT9L) and short (GLUT9S), which differ from one another by their N-terminus sequence. Each of these isoforms is localized on a different pole of the epithelial cell. The signal sequence/motif responsible for this difference is presumed to be located in the aforementioned N-terminus domain. Numerous allelic variants influencing the transport properties of the protein have also been described. The first aim of this thesis is to verify the influence of a newly discovered variant, characterized by substituting of valine for leucine in the 114th position (V114L, in the short form its corresponding variant V85L) on the ability to transport uric acid. Second aim is to verify the influence of mutations in selected motifs, which could be responsible for the localization of the protein, thus also changing its transport properties. Two dileucine motifs 12LGL14 and 33LL34 and one tyrosine motif 84YIKA87 were tested. Functional studies using 14 C radiolabeled urate demonstrated significant decrease of transport ability for the V114L/V85L allelic variant in both...
|
|
|
Epithelial uric acid transport proteins and their allelic variants
Vrzáčková, Aneta ; Tlapáková, Tereza (advisor) ; Pavelcová, Kateřina (referee)
In humans, uric acid is the end product of purine metabolism and it is excreted from the body on the one hand by the epithelium lining the tubules of the nephrons, and on the other hand by the intestinal epithelium. This work aims to verify the activity of three candidate transporters from the SLC family (SLC2215, SLC22A18 and SLC47A1) that could transport uric acid in the intestinal epithelium. Preliminary results did not demonstrate that these transporters are involved in uric acid transport in the intestinal epithelium. Furthermore, the work deals with the influence of the W75C allelic variant of the SLC17A1 transporter and the mechanism by which this variant affects the transport of urate in cells. Key words: SLC22A15, SLC22A18, SLC47A1, SLC17A1, transport, epithel, uric acid
|
|
|
Pathophysiology of urate transporters in primary gout
Pavelcová, Kateřina ; Stibůrková, Blanka (advisor) ; Doležel, Zdeněk (referee) ; Hrnčíř, Zbyněk (referee)
There are localised proteins (so-called urate transporters) in the renal proximal tubules and in the intestine, which excrete and reabsorb uric acid. Polymorphisms in the genes coding these proteins can result in the disruption of the transport function and development of hyperuricemia and gout. However the serum level of uric acid is also determined by other factors which include the intake of exogenous purines in food, synthesis of endogenous purines and degradation of nucleic acids, but also certain conditions. In 250 patients with primary hyperuricemia and gout we used Sanger sequencing to analyse the exons and adjacent intron regions in ten genes coding urate transporters: ABCG2, ABCC4, SLC2A9, SLC22A12, SLC22A11, SLC22A13, SLC17A1, SLC17A3, SLC22A6 and SLC22A8. We examined a possible connection between the identified genetic variants and primary hyperuricemia and gout based on a comparison of allele frequencies with the European population, according to topological models, according to programs predicting the functional impacts of variants and searches in specialised literature. We also took into account the conclusions of functional studies analysing the impact of nonsynonymous variants in the ABCG2 and SLC2A9 genes. We also focused on the effect of the concomitant occurrence of several...
|
|
| |
guest ::
RSS feed.