Topic 12
Lipid synthesis and detoxification.
What are the primary functions of the smooth ER?
The metabolism of reactive oxygen species (ROS) using enzyme catalase, breaking down hydrogen peroxide into water and oxygen and thereby preventing cellular damage.
What is a main function of peroxisomes?
Invagination of large molecules, particles, and even whole cells by forming a vesicle that buds off inside the cell's interior.
What is endocytosis?
These membrane transporter proteins form pores in the membrane, allowing rapid movement of small ions like sodium and potassium based on their concentration gradient.
What are channel proteins?
It pulls post-translational proteins into the ER through the translocator, recognizes misfolded and partially folded proteins, and aids in protein folding.
What is BiP, the chaperone protein?
MIM1, TOM, SAM, TIM22, TIM23 AND OXA.
What are the mitochondrial protein translocators?
They mediate the trafficking and binding of vesicles and can change the identity of an organelle.
What are Rab proteins?
They control coat assembly.
What are monomeric GTPases?
These liquid-like cellular structures lack membranes but organize cellular biochemistry.
What are Condensates?
This family of ATPases drives the recycling of peroxisomal import receptors.
What is Pex6?
This late-stage endosomal structure is hijacked by viruses like HIV to evade degradation.
What is MVB?
A group of proteins that are involved with peroxisomal protein transport
What are peroxins?
Protein transport from the cytosol into a topologically-distinct space via transmembrane protein translocators.
What is protein translocation?
The fuel used for both nuclear import and export and functions as a molecular switch that can exist in one of two conformational states depending on whether GDP or GTP is bound.
What is Ran GTPase?
This ER-localized protein assists in folding glycosylated proteins.
What is calnexin?
Found in thermophilic archaea, these unique lipids span both leaflets of the membrane, providing stability in extreme temperatures.
What are isoprenoids?
During the formation of biomolecular condensates, these macromolecules are recruited by RNA and scaffold proteins.
What are client macromolecules?
Beta-barrel proteins that have the ability to form pores permeable to metabolites/inorganic ions, but not most proteins.
What are porins?
Under an electron microscope, these structures appear convoluted and are a result of ER-derived vesicles fusing together.
What are vesicular tubular clusters?
Short ER retrieval signal that typically contains Lys-Asp-Glu-Leu at the C-terminal end; utilized by soluble ER resident proteins like BiP.
What is the KDEL sequence?