Nucleolin

Template:Short description Template:Infobox gene Nucleolin is a protein that in humans is encoded by the NCL gene.

Gene

The human NCL gene is located on chromosome 2 and consists of 14 exons with 13 introns and spans approximately 11kb. Intron 11 of the NCL gene encodes a small nucleolar RNA, termed U20.

Function

Nucleolin is the major nucleolar protein of growing eukaryotic cells. It is found associated with intranucleolar chromatin and pre-ribosomal particles. It induces chromatin decondensation by binding to histone H1. It is thought to play a role in pre-rRNA transcription and ribosome assembly. May play a role in the process of transcriptional elongation. Binds RNA oligonucleotides with 5'-UUAGGG-3' repeats more tightly than the telomeric single-stranded DNA 5'-TTAGGG-3' repeats.

Nucleolin is also able to act as a transcriptional coactivator with Chicken Ovalbumin Upstream Promoter Transcription Factor II (COUP-TFII).

Clinical significance

Midkine and pleiotrophin bind to cell-surface nucleolin as a low affinity receptor. This binding can inhibit HIV infection.

Nucleolin at the cell surface is the receptor for the respiratory syncytial virus (RSV) fusion protein. Interference with the nucleolinTemplate:NdashRSV fusion protein interaction has been shown to be therapeutic against RSV infection in cell cultures and animal models.

Interactions

Nucleolin has been shown to interact with:

• MTDH,
• CSNK2A2,
• Centaurin, alpha 1,
• HuR,
• NPM1,
• P53,
• PPP1CB,
• S100A11,
• Sjögren syndrome antigen B,
• TOP1, and
• Telomerase reverse transcriptase.