caution:PubMed:9426230 reported that this protein does not transport carnitine, however, experiments were done with the Phe-503 variant, which affects the ability to transport carnitine. PubMed:15459889 showed that, although weakly, it can also transport carnitine at some level. Its function in carnitine transport is therefore unclear.,disease:Defects in SLC22A4 may be a cause of rheumatoid arthritis (RA).,disease:Defects in SLC22A4 may be a cause of susceptibility to Crohn disease (CD) [MIM:266600]. CD is a form of remitting inflammatory bowel disease (IBD). CD may involve any part of the gastrointestinal tract, but most frequently the terminal ileum and colon. Bowel inflammation is transmural and discontinuous. CD is commonly classified as an autoimmune disease.,function:Sodium-ion dependent, low affinity carnitine transporter. Probably transports one sodium ion with one molecule of carnitine. Also transports organic cations such as tetraethylammonium (TEA) without the involvement of sodium. Relative uptake activity ratio of carnitine to TEA is 1.78. A key substrate of this transporter seems to be ergothioneine (ET).,induction:Overexpressed upon TNF-alpha treatment.,similarity:Belongs to the major facilitator superfamily. Organic cation transporter family.,subunit:Interacts with PDZK1.,tissue specificity:Widely expressed. Highly expressed in whole blood, bone marrow, trachea and fetal liver. Weakly expressed in kidney, skeletal muscle, prostate, lung, pancreas, placenta, heart, uterus, spleen and spinal cord. Highly expressed in intestinal cell types affected by Crohn disease, including epithelial cells. Expressed in CD68 macrophage and CD43 T-cells but not in CD20 B-cells. Predominantly expressed in CD14 cells in peripheral blood mononuclear cells.,
Membrane; Multi-pass membrane protein.
Widely expressed. Highly expressed in whole blood, bone marrow, trachea and fetal liver. Weakly expressed in kidney, skeletal muscle, prostate, lung, pancreas, placenta, heart, uterus, spleen and spinal cord. Highly expressed in intestinal cell types affected by Crohn disease, including epithelial cells. Expressed in CD68 macrophage and CD43 T-cells but not in CD20 B-cells. Predominantly expressed in CD14 cells in peripheral blood mononuclear cells.