[Isoform 1]: Mitochondrial isoform that catalyzes the phosphorylation of pantothenate to generate 4′-phosphopantothenate in the first and rate-determining step of coenzyme A (CoA) synthesis (PubMed:15659606, PubMed:16272150, PubMed:17242360, PubMed:17825826). Required for angiogenic activity of umbilical vein of endothelial cells (HUVEC) (PubMed:30221726). ; [Isoform 4]: Cytoplasmic isoform that catalyzes the phosphorylation of pantothenate to generate 4′-phosphopantothenate in the first and rate-determining step of coenzyme A (CoA) synthesis.