Fig. 6: NAA60-related disease mechanisms involve impaired cellular phosphate homeostasis, possibly via SLC20A2.
a Representation of sulfo-NHS-biotin labeling and pulldown to isolate plasma membrane (PM) proteins. b Western blot from human fibroblasts subjected to sulfo-NHS-biotin labeling and pulldown. c Quantification of b, in affected cases (F1-II-1 and F1-II-2), heterozygous unaffected carriers (F1-I-1), and control lines (** indicates p < 0.0005 by unpaired two-tailed t test with Welch’s correction (p = 0.0038 for case I against control and p = 0.0026 for case II against control). The results were compared to endogenous actin levels. Mean from n = 3 independent pulldowns and error bars represent SD. d Representation of the assay assessing depletion of inorganic phosphate (Pi) from culture medium. e Quantification of [Pi] in culture medium of fibroblasts from cases with variants in NAA60, SLC20A2, and healthy controls after 3 days of incubation (T1). Mean from n = 3 independent experiments shown, error bars represent SD, and * indicates p < 0.05 by unpaired two-tailed t test with Welch’s correction (p = 0.0423). e’ [Pi] depletion from T0 to T1 in fibroblast culture as in e, showing higher depletion in control (43.3%) than in NAA60 mutant culture medium (7.9%), indicating a 35.5% reduction in [Pi] uptake by NAA60 mutant fibroblasts. Mean from n = 3 independent experiments is shown, error bars represent SD, and * indicates p < 0.05 by unpaired two-tailed t test with Welch’s correction (p = 0.0423). f Efflux of 33Pi and f’ uptake of 33Pi from in PBMCs in healthy donor (Ctrl) and PFBC patient from F2 carrying the NAA60 c.338-1 G > C variant. Mean and SD from n = 6 independent experiments are shown, and * indicates p < 0.05 by unpaired two-tailed t test with Welch’s correction (p = 0.0253). g NAA60 and SCL20A2 genes module co-expression in the caudate tissue. Top–down plot of the blue and gray module genes in the caudate tissue. NAA60 module is highlighted in blue, SLC20A2 in gray. Size of gene nodes reflect their connectivity with the rest of genes in the module. Proximity of genes in the plot reflects their similarity in terms of shared connections with other genes. Error bars show SD. * indicates p < 0.05 by unpaired t test with Welch’s/correction. Source data are provided in the Source Data file. Parts of the figure were drawn by using elements modified with text, markings, and annotations from Servier Medical Art, provided by Servier, licensed under a Creative Commons Attribution 3.0 (https://creativecommons.org/licenses/by/3.0/).
