p68 RNA helicase is a nuclear protein that exhibits RNA-dependent ATPase activity. Phosphorylation by protein kinase C inhibits p68 RNA helicase activity. p68 RNA helicase appears to play a role in organ differentiation during development. Furthermore, p68 RNA helicase is expressed in early neural development and in various mesodermal tissues in a number of different chordate embryos. At the cellular level, the expression levels of p68 RNA helicase increases in serum-induced quiescent cell lines. p68 RNA helicase may function as a coactivator for estrogen receptor alpha. Additionally, p68 RNA helicase associates with transcriptional coactivators CBP and p300. p68 RNA helicase localizes to the nucleus under normal conditions. During late telophase, p68 RNA helicase and fibrillarin colocalize to nascent nucleoli. p68 RNA helicase may function as a heterodimer with p72 RNA helicase.