RT Journal Article SR Electronic T1 Gain-of-function genetic screens in human cells identify SLC transporters overcoming environmental nutrient restrictions JF Life Science Alliance JO Life Sci. Alliance FD Life Science Alliance LLC SP e202201404 DO 10.26508/lsa.202201404 VO 5 IS 11 A1 Manuele Rebsamen A1 Enrico Girardi A1 Vitaly Sedlyarov A1 Stefania Scorzoni A1 Konstantinos Papakostas A1 Manuela Vollert A1 Justyna Konecka A1 Bettina Guertl A1 Kristaps Klavins A1 Tabea Wiedmer A1 Giulio Superti-Furga YR 2022 UL https://www.life-science-alliance.org/content/5/11/e202201404.abstract AB Solute carrier (SLC) transporters control fluxes of nutrients and metabolites across membranes and thereby represent a critical interface between the microenvironment and cellular and subcellular metabolism. Because of substantial functional overlap, the interplay and relative contributions of SLCs in response to environmental stresses remain poorly elucidated. To infer functional relationships between SLCs and metabolites, we developed a strategy to identify SLCs able to sustain cell viability and proliferation under growth-limiting concentrations of essential nutrients. One-by-one depletion of 13 amino acids required for cell proliferation enabled gain-of-function genetic screens using a SLC-focused CRISPR/Cas9–based transcriptional activation approach to uncover transporters relieving cells from growth-limiting metabolic bottlenecks. Among the transporters identified, we characterized the cationic amino acid transporter SLC7A3 as a gene that, when up-regulated, overcame low availability of arginine and lysine by increasing their uptake, whereas SLC7A5 was able to sustain cellular fitness upon deprivation of several neutral amino acids. Moreover, we identified metabolic compensation mediated by the glutamate/aspartate transporters SLC1A2 and SLC1A3 under glutamine-limiting conditions. Overall, this gain-of-function approach using human cells uncovered functional transporter-nutrient relationships and revealed that transport activity up-regulation may be sufficient to overcome environmental metabolic restrictions.