Eukaryotic Compartmentalization and Protein Transport

Flashcards covering the key concepts related to eukaryotic compartmentalization, protein synthesis, and transport mechanisms.

Cytosol

The space of cytoplasm outside the membrane-enclosed organelles where the synthesis of almost all proteins begins.

Lumen

A cavity enclosed by an organelle membrane which is topologically equivalent to the exterior/outside the cell.

Signal Sorting

A process involving a signal sequence or signal patch that directs the delivery of a protein to a specific location.

Nuclear Pore Complex (NPC)

A selective gate that supports the active transport of specific macromolecules and assemblies between two topologically equivalent spaces.

Nuclear Localization Signals (NLS)

Sorting signals responsible for the selectivity of active nuclear import processes.

Nuclear Export Signals

Signals contained in the structure of molecules and complexes that are transported from the nucleus to the cytosol.

GTP-Ran

An enzyme that acts as a molecular switch, changing between two conformations, regulating transport through the NPC.

Protein Translocators

Membrane-bound proteins that mediate the transport of other proteins across membranes.

TOM complex

Transfers proteins across the outer membrane of the mitochondria.

TIM complexes

Transfers proteins across the inner membrane of the mitochondria.

Signal Sequence

A continuous amino acid sequence that directs proteins to specific organelles and is often removed upon arrival.

Signal Patch

A specific arrangement of atoms resulting from tertiary structure that is integral to protein and not removed upon arrival.