Intracellular Compartments and Protein Transport

Flashcards covering key vocabulary and concepts related to intracellular compartments and protein transport.

Sorting Signal/Signal Sequence

A sequence of amino acids that directs a particular protein to a specific destination in the cell.

Nuclear Localization Signal (NLS)

A specific signal that allows proteins to be imported into the nucleus, typically containing stretches of positively charged amino acids.

Nuclear Import Receptor

A cytosolic protein that binds to the NLS of newly synthesized proteins and guides them to the nuclear pore.

Signal Recognition Particle (SRP)

A protein-RNA complex that recognizes and binds the ER signal sequence of a nascent polypeptide, directing it to the ER.

Co-translational Import

The process by which protein import into the ER occurs simultaneously with protein synthesis.

Protein Translocator

A membrane protein that facilitates the transport of proteins across membranes, such as into the mitochondria or ER.

Signal Peptidase

An enzyme that removes the signal sequence from a newly imported protein once it reaches its destination.

Vesicular Transport

A mechanism for transporting proteins by encapsulating them in vesicles that bud off from one membrane and fuse with another.

Free Ribosomes

Ribosomes that synthesize proteins in the cytosol and are not bound to any membrane.

Membrane-bound Ribosomes

Ribosomes attached to the ER membrane that synthesize proteins destined for secretion or for use within the cell's membranes.