Required for mesendoderm differentiation (By similarity). Interacts with glucose transporters and promotes glucose uptake (PubMed:35810171). Probably augments the glucose uptake capacity of glucose transporter proteins to meet the energy needs of mesendoderm differentiation (By similarity). {ECO:0000250|UniProtKB:A0A286YD83, ECO:0000269|PubMed:35810171}. This is the function of SMIM43 (small integral membrane protein 43, Ensembl gene identifier ENSG00000164112).