FIGURE 1.

GODZ-mediates Ca²⁺ transport. A, predicted secondary structure of mouse GODZ. GODZ resembles a typical membrane transporter with four TMDs and possesses a palmitoyl acyltransferase motif (indicated by DHHC) between TMD2 and TMD3. The transmembrane mutation site of the GODZ-V61R construct is indicated in boldface. B, ⁴⁵Ca²⁺ uptake in oocytes expressing GODZ cRNA as a function of time. Oocytes were incubated with 0.5 mm ⁴⁵CaCl₂ for the indicated times. Values are means ± S.E. for 5–16 individual oocytes from three different preparations. C, summary of concentration-dependent Ca²⁺-evoked currents in GODZ-expressing oocytes. Oocytes were incubated with the indicated concentrations of Ca²⁺ for 1.0 h. The Michaelis constant determined by nonlinear regression analysis was 0.17 ± 0.01 mm. Values are means ± S.E. for 5–18 individual oocytes from three different preparations. D, surface expression of GODZ-FLAG protein in X. laevis oocytes as determined by immunofluorescence. Left panel, GODZ-FLAG-injected oocyte treated with anti-FLAG antibody showing intense surface staining; right panel, control water-injected oocyte tested with anti-FLAG antibody.