Catalyzes the phosphorylation of pantothenate to generate 4'-phosphopantothenate in the first and rate-determining step of coenzyme A (CoA) synthesis (PubMed:20559429, PubMed:22815849). Required for the hepatic CoA increase during the switch from glucose to fatty acid oxidation that occurs in the fasting state (PubMed:20559429). Catalyzes the phosphorylation of pantothenate to generate 4'-phosphopantothenate in the first and rate-determining step of coenzyme A (CoA) synthesis. Catalyzes the phosphorylation of pantothenate to generate 4'-phosphopantothenate in the first and rate-determining step of coenzyme A (CoA) synthesis. (R)-pantothenate + ATP = (R)-4'-phosphopantothenate + ADP + H(+) Strongly inhibited by non-esterified CoA (CoASH), acetyl-CoA and malonyl-CoA (PubMed:12095677). Also inhibited by palmitoyl CoA (PubMed:12095677). Inhibited by calcium hopantenate (PubMed:17379144). Strongly inhibited by acetyl-CoA and modestly by malonyl-CoA (PubMed:16040613, PubMed:10625688, PubMed:12095677). Refractory to inhibition by both CoA and palmitoyl-CoA (PubMed:16040613). Inhibited by calcium hopantenate (PubMed:17379144). Cofactor biosynthesis; coenzyme A biosynthesis; CoA from (R)-pantothenate: step 1/5. Homodimer. Highly expressed in the liver, heart and kidney. Highly expressed in the liver (PubMed:10625688, PubMed:20559429, PubMed:16040613). Expressed at lower levels in the kidney (PubMed:10625688). The N-terminal extension, may be the regulatory domain. Pank1 single knockout mice exhibit reduced hepatic CoA levels, a reduced rate of CoA-dependent fatty acid oxidation in the fasting state, impaired gluconeogenesis, and mild hypoglycemia in the fasting state (PubMed:20559429). Show a reduction in pantothenate kinase (PANK) activity of about 50% and 40% in the liver and brain respectively (PubMed:22815849). Pank1 and Pank2 double knockout mice develop progressively severe hypoglycemia and hyperketonemia by postnatal day 10 leading to their death by day 17 (PubMed:22815849). A reduction in PANK activity of about 90-95% seen in the liver and brain and hepatocytes show reduced levels of NADH (PubMed:22815849). Belongs to the type II pantothenate kinase family.