CMB1004/L03 Intracellular Compartments Flashcards
Give the 3 major types of transport.
Gated transport
Transmembrane transport
Vesicular transport
Give 2 examples of signal sequences.
Nuclear localisation signal
Mitochondrial signal sequence
Where are signal sequences targeted?
N-terminal end
Why are proteins imported into the nucleus? (3)
Structure, gene transcription and regulation
What does nucleus-cytoplasm transport occur through?
Nuclear pore complex (NPC)
What is gene transcription regulated by in activated T-cells?
NF-AT
What sequence is required for a protein to pass through the TOM/TIM complex in mitochondria?
Sigla sequence
Where does protein synthesis start?
Cytosol
Where do proteins translocate to during synthesis?
Into RER membrane or lumen
Where are mucins found?
Between epithelial cells and external mucosal surfaces
Where is the IgA1 receptor found?
On Fc region of protein
What does plgR (polymeric immunoglobulin receptor) recognise?
J chain reaction of polymerised IgA and IgM
Name a pro-inflammatory IgG variant.
IgG with galactose-deficient N-glycans
Name an anti-inflammatory IgG variant.
IgG with sialylated N-glycans
Where can proteins travel once inside the lumen or membrane or RER? (3)
Remain in RER
Travel to other organelles
Export to cell surface or be secreted
Where can water-soluble proteins travel?
Remain within organelles (lumen)
Plasma membrane
Where can membrane-associated proteins travel?
Remain within organelle membranes
Plasma membrane
What is vesicular transport essential for? (2)
Phagocytosis
Cell-to-cell communication
Quick response to environmental changes
What is linked by the trans-Golgi network?
Golgi apparatus and surrounding organelles
What do COPII protein coats cover?
ER
What do COPI protein coats cover?
Golgi cisternae
What do clathrin protein coats cover?
Vesicles secreted from the Golgi apparatus
Which direction does the cis face of the Golgi apparatus face?
Inner/vesicles enter
Which way does the trans face of the Golgi apparatus face?
Outer/vesicles leave
What modifications occur to proteins in the Golgi apparatus?
Core oligosaccharide trimmed
Further sugars added/removed
Which region are early acting enzymes found in the Golgi apparatus?
Cis
Which region are late acting enzymes found in the Golgi apparatus?
Trans
What kind of bacteria are preferentially phagocytosed by macrophages and neutrophils?
Antibody-coated bacteria
What do lysosomes contain?
Acid hydrolases
Name the 4 distinct degradation pathways in lysosomes.
Endocytosis
Macropinocytosis
Phagocytosis
Autophagy
Name 3 acid hydrolases.
Nucleases
Proteases
Glycosidases
Lipases
Phophatases
Sulfatases
Phospholipases
What is autophagy?
Degradation of unwanted proteins and organelles
What is dysfunctional autophagy associated with? (3)
Infectious disorders
Neurodegenerative diseases
Cancer
Name the 4 types of autophagy.
Macroautophagy
Microautophagy
Chaperone-mediated autophagy
Selective autophagy
What is another name for selective autophagy?
Xenophagy
What is microautophagy?
Uptake of cytoplasmic components by inward invagination of lysosomal membranes
What is chaperone-mediated autophagy?
Direct transport of cytosolic proteins into lysosomes through translocons
Name 2 types of secretory pathway.
Constitutive
Regulated
What is a chimera?
An organism or tissue that contains at least two different sets of DNA, often from zygote fusion
