Protein Transport Flashcards
Where are most proteins synthesised?
Cytosol
Few inside mitochondria
What is the signal hypothesis?
Blobel, 1975
All proteins that need to be stored inside the cell have a signal sequence
(Signals directing movement)
What are the modes of protein transport?
Gated transport
Transmembrane transport
Vesicle transport
What is considered a typical mitochondria-targeting sequence?
An N terminal ampipathic a-helix
What is considered a typical ER targeting sequence?
An N terminal stretch of hydrophobic residues
What is considered a typical nucleus localisation signal?
A stretch of positively charged residues
How are proteins transported in gated transport?
In a folded state through nuclear pore complexes
Is gated transport bi-directional or unidirectional?
Bi-directional
How are proteins transported in transmembrane transport?
Sneak through membrane translocators usually in an unfolded state
How are proteins transported in vesicular transport?
Proteins are moved in vesicles
Is vesicular transport bi-directional or unidirectional?
Bi-directional
What are the two types of secretion?
Constitutive constriction
Regulated constriction
What modes of intracellular transport are energy-dependent?
Nuclear protein import
Nuclear protein export
Translocation of mitochondrial matrix proteins
Which modes of intracellular protein transport are transported in a folded state?
Nuclear protein export
Nuclear protein import
Vesicular transport
What is an example of a co-translational protein transport?
Translocation of ER proteins
