Intracellular Membrane Traffic

Which family of coat-recruitment GTPases is responsible for the assembly of both COPI and clathrin coats at Golgi membranes?

What is the primary function of the protein dynamin in the formation of clathrin-coated vesicles?

In the context of receptor-mediated endocytosis, what is the fate of the Low-Density Lipoprotein (LDL) after it dissociates from its receptor in the low pH environment of the early endosome?

What type of signal directs soluble ER resident proteins, like BiP, back to the ER from the Golgi apparatus?

The ESCRT protein complexes are essential for which of the following topologically equivalent processes?

Which condition is necessary for the KDEL receptor to bind tightly to its KDEL-containing ligand proteins?

In the process of regulated secretion, what is the primary trigger that causes secretory vesicles to fuse with the plasma membrane and release their contents?

According to the cisternal maturation model of Golgi transport, how are Golgi resident enzymes maintained in their correct cisternae?

What is the typical diameter of a synaptic vesicle, a specialized class of tiny secretory vesicles found in nerve cells?

In polarized epithelial cells, where are proteins linked to the lipid bilayer by a glycosylphosphatidylinositol (GPI) anchor predominantly found?

What is the primary function of the coat protein complex retromer?

During receptor-mediated endocytosis of the transferrin receptor, what causes the iron-free transferrin (apotransferrin) to dissociate from its receptor?

What is the role of the NSF protein in membrane trafficking?

In the condition known as I-cell disease, a defect in which enzyme leads to the mis-sorting of lysosomal hydrolases?

Which statement accurately describes the function of caveolae?

What is the approximate internal pH of a lysosome, which is required for the optimal activity of its acid hydrolases?

The process where a cell engulfs parts of its own cytosol or entire organelles into a double-membraned structure for delivery to the lysosome is called:

What is the function of tethering proteins in vesicle transport?

Which statement accurately describes the default secretory pathway from the trans-Golgi network (TGN)?

How much of its own volume of fluid does a macrophage ingest each hour through pinocytosis?

What is the key structural feature of a clathrin molecule that allows it to form polyhedral cages?

The adaptor protein AP2, which links clathrin to cargo receptors, undergoes a conformational change that exposes its cargo-binding sites upon interaction with which molecule in the plasma membrane?

What is the name of the structures formed when ER-derived COPII-coated vesicles fuse with one another before reaching the Golgi apparatus?

How does the process of autophagy differ from phagocytosis?

The final destination for proteins that follow the constitutive secretory pathway from the TGN in an unpolarized cell is:

Which protein is responsible for initiating the assembly of COPII coats on the ER membrane?

What is transcytosis?

Which of the following is a key feature of selective autophagy?

What is the role of the proteins Pink1 and Parkin in mitophagy?

What is the estimated net concentration increase of a secretory protein from its initial state in the ER to its final state in a mature secretory vesicle?

What are the two primary functions of the protein coat on a transport vesicle?

v-SNAREs and t-SNAREs are complementary sets of proteins that mediate membrane fusion. Where are they typically found?

What is the primary purpose of the quality control mechanism in the ER that retains misfolded or incompletely assembled proteins?

In the exocytosis of synaptic vesicles, what is the direct role of synaptotagmin?

Proteolytic processing of secretory proteins, such as converting pro-hormones to active hormones, occurs primarily in which locations?

The lumen of which of the following compartments is NOT topologically equivalent to the cell exterior?

Which class of proteins do SNAREs belong to?

What type of vesicle mediates the retrieval of escaped ER resident proteins from the vesicular tubular clusters and the Golgi?

What happens to the Rab protein after vesicle fusion is complete?

A newborn baby obtains antibodies from its mother's milk, which are transported across the epithelial cells of its gut into the bloodstream. This process is an example of:

The degradation of an endocytosed signaling receptor like the EGF receptor is terminated when it is sequestered into which structures?

How many different SNARE proteins are present in a typical animal cell?

Which of the following describes the composition of a typical t-SNARE?

What is the function of the Rab cascade, for example the conversion of a Rab5-domain to a Rab7-domain on an endosome?

Which part of the Golgi apparatus is described as a collection of fused vesicular tubular clusters arriving from the ER?

What type of chemical modification is used to target certain signaling receptors, like the EGF receptor, for degradation via the endocytic pathway?

In the process of phagocytosis, what triggers a phagocyte to extend pseudopods to engulf a target particle?

What is the primary role of the protein complexin at the synapse?

How is the symmetrical distribution of phospholipids in the two leaflets of the ER membrane generated?

What is the primary mechanism by which macromolecules are sequestered into biomolecular condensates?