However, PCP has little affinity for the human monoamine transporters, including the dopamine transporter (DAT). Transport is mediated by ATP binding cassette transporters. HRT may promote reverse cholesterol transport through induction of cholesterol ABC transporters. Sav1866 is a homolog of multidrug ABC transporters. Amino acids are reabsorbed by sodium dependent transporters in the proximal tubule. SPECT is used to detect these abnormalities in Dopamine transporters. Inhibitory effects on 5-HT, norepinephrine, and dopamine transporters are weak. Reserpine irreversibly blocks the H-coupled vesicular monoamine transporters, VMAT1 and VMAT2. Ammonium ions are absorbed by the plant via ammonia transporters. Collectively membrane transporters and channels are transportome. Methylphenidate binds to and blocks dopamine transporters (DAT) and norepinephrine transporters. They are also involved in apoptosis, modulation of activities of transporters, and membrane-bound enzymes. This process requires modification of the auxin transporters (PIN proteins). The other four families are porins, iron transporters, flagellum-associated proteins, and proteins of unknown function. Membrane vesicle trafficking is needed for the correct positioning of several hormone transporters.