Construction of human GGCX/VKD protein expression vectors
The cDNAs of VKD proteins (UCMA/GRP, MGP, BGLAP, PRGP1, TMG4, GAS6) together with a c-myc tag at the C-terminus were cloned into MCSA bicistronic vector pIRES (Clontech). The wildtype (wt) human GGCX(hGGCX ) cDNA was cloned into MCSB of the bicistronic vector.GGCX variants (mut) were introduced by site directed mutagenesis. The reference number of GGCX DNA and protein sequence were RefSeq NM_000821.7 and NP_000821.2, respectively. The GGCX variants were validated by VariantValidator online tool (https://variantvalidator.org/; accessed on 09.04.2021).