equilibrative nucleoside transporter 4 (hENT4, solute carrier family 29 member 4, plasma membrane monoamine transporter, SLC29A4, ENT4, PMAT, PSEC0113)

Function: - polyspecific organic cation transporter - efficiently transports many organic cations such as monoamine neurotransmitters 1-methyl-4-phenylpyridinium & biogenic amines including serotonin, dopamine, norepinephrine & epinephrine - may play a role in regulating central nervous system homeostasis of monoamine neurotransmitters - may be involved in luminal transport of organic cations in the kidney - seems to use luminal proton gradient to drive organic cation reabsorption - does not seem to transport nucleoside & nucleoside analogs such as uridine, cytidine, thymidine, adenosine#, inosine, guanosine, & azidothymidine # adenosine is transported [2] may play a role in the regulation of extracellular adenosine concentrations in cardiac tissues, in particular during ischemia [2] Structure: - N-glycosylated - belongs to the SLC29A transporter family Compartment: - membrane (putative) - located to the plasma membranes of ventricular myocytes & vascular endothelial cells - targeted to the apical membranes of differentiated kidney epithelial cells Alternative splicing: named isoforms=2 Expression: - expressed abundantly in the heart, in both cardiomyocytes & vascular endothelial cells (at protein level) - highly espressed in brain, kidney & skeletal muscle - in the brain expressed in cerebellum, cerebral cortex, medulla, occipital pole, frontal & temporal lobes putamen & in the spinal cord lower expression in liver, pancreas, & liver - expressed in endometrial tissue, exclusively in the stroma - expression is high in the proliferative phase, decreases during the secretory phase, & is no longer detectable in the menstrual phase

General

glycoprotein phosphoprotein solute carrier family 29 (SLC29, SLC29A) transmembrane 10e protein

Properties

SIZE: entity length = 530 aa MW = 58 kD COMPARTMENT: cellular membrane MOTIF: exoplasmic domain {1-68} transmembrane domain {69-89} cytoplasmic loop {90-101} transmembrane domain {102-122} exoplasmic loop {123-139} transmembrane domain {140-160} cytoplasmic loop {161-166} transmembrane domain {167-187} exoplasmic loop {188-231} MOTIF: Thr phosphorylation site {T220} transmembrane domain {232-252} cytoplasmic loop {253-351} transmembrane domain {352-372} exoplasmic loop {373-381} transmembrane domain {382-402} cytoplasmic loop {403-416} transmembrane domain {417-437} exoplasmic loop {438-450} transmembrane domain {451-471} cytoplasmic loop {472-486} transmembrane domain {487-509} exoplasmic domain {510-530} MOTIF: N-glycosylation site {N523}

Database Correlations

UniProt Q7RTT9 Pfam PF01733 Kegg hsa:2229