Pantothenate kinase, PanK, is a vital regulatory enzyme for coenzyme A (CoA) biosynthesis, phosphorylating pantothenate (vitamin B5) to 4-phosphopantothenate, then quickly transforming to CoA which is an essential component for fatty acid metabolism (Abiko, Y, 1967). There are 4 members of the PanK family, located on chromosomes 10q23.31, 20p13, 5q35, and 1p36.32 (Zhou et al, 2001). PanK1 is predominantly in heart, liver, and kidney. PanK2 is expressed ubiquitously, with higher levels in retinal and infant basal ganglia. PanK3 has high levels in liver, while PanK4 is expressed ubiquitously with its highest levels found in muscle (Zhou et al, 2001). Additionally, PanK4 has been shown to regulate Pkm2 activity affecting glucose metabolism (Li et al, 2005). There have been several phospho-serine, threonine, and tyrosine sites identified within PanK4, the role of each one has yet to be determined.
