Cell culture and characterization protocol

SH-SY5Y (ATCC Cat# CRL-2266, RRID:CVCL_0019) and HEK293T (ATCC Cat# CRL-3216, RRID:CVCL_0063) cells were cultured in Dulbecco’s modified Eagle’s medium (DMEM) supplemented with 10% fetal bovine serum (FBS) and 100 μg/ml penicillin and streptomycin (Hyclone) at 37°C in 10% CO₂. HEK293T cells deficient for COG subunits were generated as described in (Blackburn and Lupashin, 2016 (link)). Two lines of Menkes deficient fibroblasts were used: one in conjunction with a rescue line expressing recombinant ATP7A (described in La Fontaine et al., 1998 (link)) and the other in conjunction with a familial control (Coriell GM01981 and GM01983). The former was cultured in DMEM supplemented with 10% FBS and 100 μg/ml penicillin and streptomycin at 37°C in 5% CO₂, while the latter were cultured in minimum essential media (MEM) (Thermo Fisher 11095080) supplemented with 15% FBS and 100 μg/ml penicillin and streptomycin at 37°C in 5% CO₂. Antibodies and primers can be found in Supplementary file 1. Cell were tested for mycoplasma infection using the MycoAlert Mycoplasma Detection Kit from Lonza. None of the cell lines used in this study belong to the Database of Cross-Contaminated or Misidentified Cell Lines defined by the International Cell Line Authentication Committee.