Protein Trafficking through the Endomembrane System

Flashcards summarizing key vocabulary and concepts related to protein trafficking through the endomembrane system.

Endomembrane System

A system of membranes that includes the endoplasmic reticulum, golgi apparatus, vesicles, lysosomes, and the cell membrane, involved in the trafficking of proteins.

Vesicle Budding

The process by which vesicles form from a donor membrane, carrying cargo proteins for transport.

COPII

A coat protein that mediates the transport of vesicles from the rough endoplasmic reticulum to the Golgi.

Retrograde Transport

The movement of materials back to the donor compartment or the previous cell compartments within the endomembrane system.

Guanine nucleotide exchange factor (GEF)

A protein that promotes the exchange of GDP for GTP, activating G-proteins like Sar1 for vesicle formation.

v-SNARE and t-SNARE

Proteins located on vesicles and target membranes, respectively, that interact to facilitate vesicle docking and fusion.

Endocytosis

The process through which cells internalize substances from their external environment via vesicle formation.

Exocytosis

The process of vesicle fusion with the plasma membrane to release contents outside the cell.

Lysosome

A membrane-bound organelle containing hydrolytic enzymes for digestion of macromolecules.

Phagocytosis

A type of endocytosis where large particles, such as bacteria, are engulfed by the cell.

Clathrin-coated Vesicles

Vesicles enveloped in clathrin protein that transport molecules to endosomes or lysosomes.

Cisternal Maturation Model

A model describing how Golgi cisternae mature as they move from the cis to trans side, carrying cargo proteins.

Glycosylation

The addition of sugars to proteins; this process begins in the endoplasmic reticulum and continues in the Golgi.

Adaptor proteins

Proteins that connect cargo proteins to coat proteins, facilitating the formation of vesicles.

Rab G-protein

A small GTPase involved in vesicle trafficking; it helps in docking vesicles to the target membrane.

Transport Vesicles

Small, membrane-bound sacs that transport proteins and lipids between different cellular compartments.

Golgi Apparatus

An organelle responsible for the modification, sorting, and packaging of proteins delivered from the endoplasmic reticulum.

Constitutive Secretion

The continuous release of proteins from the cell without the need for a specific signal.

Receptor-mediated Endocytosis

A selective form of endocytosis where cells internalize molecules bound to specific receptors.