What is nuclear export receptor?

A nuclear export signal (NES) is a short target peptide containing 4 hydrophobic residues in a protein that targets it for export from the cell nucleus to the cytoplasm through the nuclear pore complex using nuclear transport.

What happens nuclear transport?

Nuclear transport refers to the mechanisms by which molecules move across the nuclear membrane of a cell. The entry and exit of large molecules from the cell nucleus is tightly controlled by the nuclear pore complexes (NPCs).

How is nuclear transport regulated?

Importantly, nuclear transport is regulated at multiple levels via a diverse range of mechanisms, such as the modulation of the accessibility and affinity of target signal recognition by importins/exportins, with phosphorylation/dephosphorylation as a major mechanism.

Which of the following choices would have the biggest effect on nuclear transport?

Loss of RanGAP would affect both import and export, having the largest detrimental effect on nuclear transport.

What goes in and out of nuclear pores?

Each nuclear pore is a large complex of proteins that allows small molecules and ions to freely pass, or diffuse, into or out of the nucleus. Nuclear pores also allow necessary proteins to enter the nucleus from the cytoplasm if the proteins have special sequences that indicate they belong in the nucleus.

Why is nuclear import important?

Nuclear import of proteins is an essential step in regulating gene expression and the replication cycle of several viruses. In this review, the key mechanisms, pathways, and models underlying the transport of proteins across nuclear pores are analysed.

What are nuclear import factors?

There are four important factors for the nuclear transport: (1) nucleoporins (NUPs) that are constituent proteins of NPCs, (2) RanGTPase that allows for active transport and directionality, (3) karyopherins (importin/exportin/transportin) that can recognize cargo molecules, (4) nuclear localization signals (NLSs) or …

What causes nuclear import receptors to release their cargo once in the nucleus?

The import receptors with their bound cargo then move along tracks lined by FG-repeat sequences until they reach the nuclear side of the pore complex, where Ran-GTP binding causes the import receptors to release their cargo (Figure 12-17).