The Nuclear Pore Complex: Nuclear Import, Export, & RAN

The video tutorial explains the nuclear pore complex (NPC) and its crucial role in regulating the import and export of molecules in and out of the nucleus. It details the nuclear import process, highlighting the importance of nuclear localization sequences (NLS) and the role of importin and RAN GTPase. The tutorial also covers the nuclear export process, focusing on nuclear export sequences (NES) and the function of exportin and RAN GTPase. The mechanisms ensure that only specific proteins with the correct sequences are transported, maintaining cellular function.

What is the primary function of the nuclear pore complex (NPC)?

• To synthesize proteins

• To regulate the movement of molecules in and out of the nucleus

• To replicate DNA

• To produce energy for the cell

Which sequence is necessary for a protein to be imported into the nucleus?

• Signal peptide

• Nuclear localization sequence (NLS)

• Transmembrane domain

• Nuclear export sequence (NES)

What role does the G protein RAN play in nuclear import?

• It facilitates the release of proteins inside the nucleus

• It degrades RNA

• It binds to DNA

• It synthesizes proteins

What happens to importin after it releases its cargo inside the nucleus?

• It is degraded

• It binds to another protein

• It moves back to the cytoplasm

• It stays in the nucleus permanently

What is the nuclear export sequence (NES) primarily composed of?

• Lysine residues

• Leucine residues

• Arginine residues

• Glycine residues

How does RAN GTP facilitate nuclear export?

• By binding to DNA

• By degrading proteins

• By hydrolyzing ATP

• By binding to exportin and the protein with NES

What ensures that only proteins with an NES are exported from the nucleus?

• The presence of importin

• The charge of the protein

• The nuclear pore complex recognizing exportin

• The size of the protein