Ch 9 Nucleus Flashcards
Is traffic through nuclear pore unidirectional?
No, import and export
experiment to determine if NLS is sufficient for protein transport into the nucleus
Inject protein into cytoplasm and monitor movement of protein
Define RNA and role
Ribosomal nucleic acid: code DNA
Property of nuclear pore
Small opening in nuclear membrane
How was nuclear pore discovered
Electron microscapy
How does Leptomycin function in human cells?
Blocks nuclear export of REV by binding Crm 1 and disrupting ability to bind to Nuclear Export Signals (NES)
2 Roles and Functions of IkB
Promotes Export, inhibits NF-kB
T/F Nucleus is completely filled with chromatin
False
What do Nuclear Lamin Proteins make?
Multiprotein Complexes
How does tRNA export from nucleus and how is Ran involved.
tRNA exports via Ran-GTP. Ran-GAP inhibits Ran- GTP.
Nucleus advantage
Regulation and cell differentiation
Define Nucleolus
Region inside nucleus where ribosomes are produced.
What protein binds to Nuclear Localization Signals (NLS) as part of nuclear protein transport
Cytoplasmic receptors
What is Importin cargo
NLS
What is exportin cargo
NES
Define Heterochromatin
Highly condensed part of genome. Does not get transcribed.
Feature of transport across Nuclear Envelope
Proteins move through nuclear pore via active transport
What ensures that cargo-protein complex does not exit NPC after it enters the nucleus
Ran-GTP
How is mRNA processing linked to MRNA export from nucleus
Proteins that transcribe mRNA Package it for export.
