Vesicular Traffic, Secretion, and Endocytosis

These vocabulary flashcards cover key concepts related to vesicular traffic, secretion, and endocytosis as outlined in the lecture notes.

Vesicular Traffic

The process by which proteins and small molecules are transported between membrane-bounded compartments within a cell.

Secretory Pathway

The series of steps through which proteins are synthesized, modified, and delivered to their final destinations.

Endocytosis

The process of internalizing substances from the extracellular environment into the cell.

Autophagy

A cellular degradation process in which cells recycle cytoplasmic components, including damaged organelles.

Coated Transport Vesicles

Vesicles that form from a membrane to transport cargo proteins and are characterized by a protein coat.

Rough Endoplasmic Reticulum (ER)

The site of protein synthesis and initial folding; has ribosomes on its surface.

Covalent Modifications

Chemical modifications of proteins that can affect their function, including glycosylation.

Golgi Complex

An organelle involved in modifying, sorting, and packaging proteins for secretion or delivery to other organelles.

Anterograde Transport

The forward transport of proteins from the ER to the Golgi apparatus.

Retrograde Transport

The movement of proteins from the Golgi back to the rough ER.

Cisternal Maturation

The process where cis-Golgi cisternae mature to trans-Golgi cisternae in the Golgi apparatus.

Trans-Golgi Network

The final Golgi structure where proteins are sorted to their final destinations.

Exocytosis

The process by which vesicles fuse with the plasma membrane to release their contents outside the cell.

Constitutive Secretion

The continuous release of proteins from cells, independent of external signals.

Regulated Secretion

The release of proteins stored in secretory granules, triggered by specific signals.

Clathrin-Coated Vesicles

Vesicles that transport proteins from the plasma membrane and trans-Golgi network to endosomes.

v-SNAREs

Vesicle-associated SNARE proteins that mediate the fusion of vesicles with target membranes.

t-SNAREs

Target membrane-associated SNARE proteins that work with v-SNAREs to facilitate membrane fusion.

Rab GTPases

Small GTP-binding proteins that control vesicle trafficking and docking.

Glycosyltransferases

Enzymes that modify carbohydrates attached to proteins as they move through the Golgi.

Lysosomes

Organelles responsible for degrading macromolecules and recycling cellular components.

Mannose 6-Phosphate (M6P)

A marker that tags lysosomal enzymes for transport to lysosomes.

Hsp70

A heat shock protein that assists in the folding and stabilization of proteins.

Dynamin

A cytosolic protein necessary for the pinching off of clathrin-coated vesicles during endocytosis.

Ubiquitin

A small protein that tags other proteins for degradation or sorting within the cell.

Adapter Proteins (AP)

Proteins that facilitate the recruitment of cargo into budding vesicles.

Guanine Nucleotide Exchange Factors (GEFs)

Proteins that facilitate the exchange of GDP for GTP, activating GTP-binding proteins.

Sec Proteins

Proteins involved in vesicle formation and transport in the secretory pathway.

ESCRT Complexes

Endosomal sorting complexes required for transport, involved in the inward budding of membranes.

Proproteins

Inactive precursors that require proteolytic cleavage to become active.

Multivesicular Endosome

An endosome that contains multiple small vesicles and is involved in protein sorting.

Protein Disulfide Isomerase

An enzyme that assists in the formation of disulfide bonds in proteins.

GTP-binding Protein

A protein that can bind and hydrolyze GTP, regulating various cellular processes.

Transport Vesicles

Membrane-bound structures that ferry proteins and cargo between cellular compartments.

Sorting Signals

Amino acid sequences or signals that determine the destination of proteins.

Golgi Cisternae

Flattened membrane-bound compartments within the Golgi apparatus.

Cis-Golgi Network

The entry point of proteins into the Golgi apparatus from the ER.

Trans-Golgi Cisternae

The exit point of proteins from the Golgi apparatus to their final destinations.

Proteolysis

The breakdown of proteins into smaller peptides or amino acids.

Transmembrane Protein

Proteins that span across the plasma membrane and often function as receptors.

Protein Folding

The process by which a protein assumes its functional three-dimensional structure.

Endocytic Pathway

The transport pathway by which cells internalize extracellular materials.

Late Endosome

An endosomal compartment that acts as an intermediate in sorting to lysosomes.

Chaperone Proteins

Proteins that assist in the proper folding and assembly of other proteins.

Transforming Growth Factor beta (TGF-beta)

A cytokine involved in cell growth, proliferation, differentiation, and regulation.

Apoptosis

The process of programmed cell death that is essential for maintaining cellular homeostasis.

Low-Density Lipoprotein (LDL)

A lipoprotein that carries cholesterol in the bloodstream and is taken up by receptor-mediated endocytosis.

Exoplasmic Domain

The portion of a transmembrane protein that extends outside of the cell.

pH-sensitive Dissociation

The process by which receptor-ligand complexes release their ligand in response to changes in pH.

Antibody Recycling

The process through which antibodies are internalized and then returned to the cell surface.

Cytosolic Cargo Protein

Proteins located in the cytosol that can be delivered to lysosomes for degradation.

Signal Transduction

The process by which a cell responds to stimuli through specific pathways.

Light Chain and Heavy Chain

The two components of a clathrin molecule that form the triskelion structure.

Cell Surface Receptors

Proteins that bind ligands and mediate intracellular signaling and endocytosis.

Cytosolic Retention Signals

Signals that prevent proteins from being transported out of specific cellular compartments.