Q14978

Nopp140 also known as p130, NOLC1 is a nucleolar phosphoprotein that plays a crucial role in cellular processes by functioning as both a chaperone for protein import and export from the nucleolus and as a transcription factor. Nopp140′s ability to interact with RNA Polymerase and general transcription factor TFIIB highlights its importance in gene expression regulation. Nopp140 is heavily phosphorylated by casein kinase II, which is essential for binding to nuclear localization signals, thereby facilitating nucleolar transport and function. Nopp140 also colocalizes with NAP57, another nucleolar protein, suggesting a collaborative role in nucleolar activities, which are vital for ribosome biogenesis and cellular growth.