The Nucleus and ER Flashcards
Where does the ER start?
At the nuclear membrane.
What is the interior if the ER topologically equivalent?
The extracellular environment
Is the interior of the nucleus topologically different to the cytosol?
No.
How do proteins enter the nucleus?
Through pores.
What kind of direction code encodes for import into the nucleus?
Highly positive ones.
How many membranes enclose the nucleus?
Two
What kind of proteins are on the nuclear pores on the cystolic side of the nuclear membrane?
Fibrils.
What kind of proteins are on the nuclear pores on the nuclear side of the nuclear membrane?
Ring proteins.
What kind of proteins are found in the pores?
Nucleoporins.
What do nucleoporins recognise?
Positively charged amino acids.
What does import of proteins into the nucleus depend on?
Nuclear import receptors.
What is the process of a protein entering the nucleus?
The protein with a cargo binds to a nuclear import receptor and is recognised by the cystolic fibril. The GTP then transfers the cargo to the nucleus.
Does the transfer of proteins in and out of the nucleus require energy?
Yes.
Where does co-translational translocation occur?
In the RER.
Where does post-translational translocation occur?
In free ribosomes.
