Drosophila ZnT1 (dZnT1) and its close homolog CG5130 export zinc from the gut for systemic use. (A) Reverse transcriptase (RT)-PCR analysis of the knockdown effect of CG5130-RNAi. rp49 was used as the loading control. (B) Membrane localization of CG5130 in Caco-2 cells. Enhanced green fluorescent protein (eGFP)-tagged CG5130 is shown in green. Scale bars = 10 μm. (C) Reduced alkaline phosphatase (ALP) activity of whole body minus gut in gut-specific CG5130-RNAi larvae raised on zinc-limited food (0.1 mmol/l EDTA), with little change in aconitase activity. Genotypes of the flies are NP3084/+ (gut-specific control fly) and NP3084/CG5130-RNAi (gut-specific CG5130-RNAi fly). Values are presented as means ± SEM; n ≥ 3. *P < 0.05, **P < 0.01, ***P < 0.001; one-way ANOVA. (D) Zinpyr-1 staining showing intracellular zinc reduction caused by expressing CG5130 in Chinese hamster ovary (CHO) cells. Scale bars = 10 μm. (E) Gut-specific knockdown of CG5130 plus dZnT1 further exacerbated the phenotype on EDTA-supplemented food.