Characterization of SLCO5A1/OATP5A1, a Solute Carrier Transport Protein with Non-Classical Function

Abstract

Organic anion transporting polypeptides (OATP/SLCO) have been identified to mediate the uptake of a broad range of mainly amphipathic molecules. Human OATP5A1 was found to be expressed in the epithelium of many cancerous and non-cancerous tissues throughout the body but protein characterization and functional analysis have not yet been performed. This study focused on the biochemical characterization of OATP5A1 using Xenopus laevis oocytes and Flp-In T-REx-HeLa cells providing evidence regarding a possible OATP5A1 function. SLCO5A1 is highly expressed in mature dendritic cells compared to immature dendritic cells (∼6.5-fold) and SLCO5A1 expression correlates with the differentiation status of primary blood cells. A core- and complex- N-glycosylated polypeptide monomer of ∼105 kDa and ∼130 kDa could be localized in intracellular membranes and on the plasma membrane, respectively. Inducible expression of SLCO5A1 in HeLa cells led to an inhibitory effect of ∼20% after 96 h on cell proliferation. Gene expression profiling with these cells identified immunologically relevant genes (e.g. CCL20) and genes implicated in developmental processes (e.g. TGM2). A single nucleotide polymorphism leading to the exchange of amino acid 33 (L→F) revealed no differences regarding protein expression and function. In conclusion, we provide evidence that OATP5A1 might be a non-classical OATP family member which is involved in biological processes that require the reorganization of the cell shape, such as differentiation and migration.

Interferon Alpha Signalling and Its Relevance for the Upregulatory Effect of Transporter Proteins Associated with Antigen Processing (TAP) in Patients with Malignant Melanoma

“…Experiments were performed as previosly described [ 37 ] with modifications. cDNA was produced from 0.5–1 μg total RNA with the SuperScript® III Platinum®Two Step qRT-PCR Kit (Life Technologies, Invitrogen) or the Transcriptor First Strand cDNA Synthesis Kit (Roche Diagnostics, Mannheim, Germany).…”

Expression‐level dependent perturbation of cell proteostasis and nuclear morphology by aggregation‐prone polyglutamine proteins

“…Stable cell lines produced by traditional methods can also have problems of reproducibility due to variable copy number of the introduced gene and lack of control over the integration site. The Flp-In system, where a construct is introduced into a previously engineered integration site in the genome, circumvents these issues and has been used where consistency of expression level is crucial, for example, in studies of enzyme (Luchansky et al, 2003) or transporter (Sebastian et al, 2013) activity or protein interaction (Kohli et al, 2014), or where other factors, such as the effect of triplet repeat expansion on gene expression (Solvsten and Nielsen, 2011), are under investigation. The inducible nature of our promoter library allows the use of genes whose expression could be toxic, or at least disruptive, to the cell.…”

A network analysis to identify mediators of germline-driven differences in breast cancer prognosis

“…SULF1 has been found to be involved in cell proliferation, migration, and invasion as well as drug-induced apoptosis in cancer cell lines 19 , most likely due to its regulatory role in fibroblast growth factor 20 and Wnt signaling 21 . Less is known about the function of SLCO5A1, although a role in cell proliferation has been suggested 22 . In line with the single variant analysis, we found no significant genes for all breast cancer or ER-negative breast cancer ( Fig.…”