Disease relevance of SLC26A8

• Mutational analysis of the human SLC26A8 gene: exclusion as a candidate for male infertility due to primary spermatogenic failure [1].
• Significantly higher doses of cortisol were needed for half-maximal induction on the TAT-1 (P < 0.002), TAT-3 (P < 0.03), or mouse mammary tumor virus (P < 0.02) promoters, whereas maximal induction was not different [2].
• Finally, we show that Y47 is critical for Tat1 to function in reverse transcription, but not HIV-1 gene expression [3].
• Expression of tumor-associated trypsinogens (TAT-1 and TAT-2) in prostate cancer [4].
• Activity of human immunodeficiency virus type 1 promoter/TAR regions and tat1 genes derived from individuals with different rates of disease progression [5].

High impact information on SLC26A8

• We have determined the concentrations of two tumor-associated trypsinogen (TAT) isoenzymes, called TAT-1 and TAT-2, in human ovarian tumor cyst fluid using monoclonal antibody-based immunofluorometric assays specific for each isoenzyme [6].
• More detailed characterization by immunohistochemistry and/or in situ hybridization localized SLC26A7 to distal segments of nephrons, SLC26A8 to developing spermatocytes, and SLC26A9 to the lumenal side of the bronchiolar and alveolar epithelium of lung [7].
• We report the expansion of the SLC26 gene family by characterizing three novel tissue-specific members, named SLC26A7, SLC26A8, and SLC26A9, on chromosomes 8, 6, and 1, respectively [7].
• Tat1, a novel sulfate transporter specifically expressed in human male germ cells and potentially linked to rhogtpase signaling [8].
• Two-hybrid and in vitro binding assays demonstrate that MgcRacGAP stably interacts through its NH(2)-terminal domain with the Tat1 COOH-terminal region [8].

Biological context of SLC26A8

• The presence of HIV-1 and HIV-2 trans-activator proteins, tat1 and tat2, respectively, greatly increases viral gene expression from their homologous LTRs [9].
• Using a cervical carcinoma cell line (SiHa), E2 enhancement of URR-directed gene expression was elevated in the presence of extracellular tat1 or during cocultivation with HIV-1-infected cells [10].

Anatomical context of SLC26A8

• SLC26A8 is an anion transporter that is solely expressed in the testes [1].
• On testis sections, Tat1 protein can be immunodetected in spermatocytes and spermatids associated with plasma membrane [8].
• The hTAT1 mRNA was detected at high levels in the heart, placenta, liver, skeletal muscle, kidney, pancreas, spleen, thymus and prostate [11].
• Therefore, LAT2 and TAT1 play essential roles in the reabsorption of neutral amino acids from the epithelial cells to the blood stream in the kidney [11].

Associations of SLC26A8 with chemical compounds

• Expression of Tat1 protein in COS7 cells generates a 4,4'-diisothiocyano-2,2'-disulfonic acid stilbene and chloride-sensitive sulfate transport [8].
• In sodium dodecyl sulfate (SDS)-gel electrophoresis, the TAT-1 and TAT-2 isoenzymes have relative molecular weights (Mr) of 25,000 and 28,000, respectively, TAT-2 being the major component [12].
• Isoelectric focusing in the presence of urea gives pI values of about 5 and 4 for TAT-1 and -2, respectively [12].
• For amino acceptor cosubstrates, either oxaloacetate or alpha-ketoglutarate can be utilized equally well by TAT-1, while the former is the most effective alpha-keto acid for TAT-2 and the latter is the best for TAT-3 [13].

Other interactions of SLC26A8

• In situ hybridization studies demonstrate that Tat1 and MgcRacGAP genes are coexpressed in male germ cells at the spermatocyte stage [8].

Analytical, diagnostic and therapeutic context of SLC26A8

• TAT mRNA was demonstrated in tissue sections and identified as TAT-1 and -2 by RT-PCR and DNA-sequencing [4].

References