9 - SNAREs II Flashcards
What happens when you inhibit membrane fusion in animals?
They become paralysed as a result of Comatose a gene that encodes for NSF and Shibire a gene that codes for dynamin being restricted.
What happens to mice when VAMP2 is knocked out?
They die at birth due to a loss of synaptic transmission.
What happens to mice when Syntaxin1A is knocked out?
No gross abnormalities subtle defects in synaptic transmission.
What happens to mice when Syntaxin1B is knocked out?
They die at birth, also have reduced synaptic transmission.
What happens to mice when SNAP25 is knocked out?
They die at birth due to a loss of synaptic transmission.
What rare diseases in humans can arise form a mutation in VAMP2?
Neurodevelopmental disorders with hypotonia, autistic features with or without hyper-kinetic movements.
What rare diseases in humans can arise form a mutation in SNAP29?
Cerebral dysgenesis, neuropathy, ichthyosis and palmoplantar keratoderma syndrome.(CEDNIK)
What rare diseases in humans can arise form a mutation in Syntaxin II?
Familial hemophagocytic lymphohistocytosis type 4 (FHL4)
What does S75P do to liposome function?
Slows it down.
How is the biological acitvity of SNARE proteins measured?
- synthetic membranes one with VAMP2 and another with syntaxin on it are taken.
- Fluorescent dye would be put on one of the liposomes which would be quenched.
- there is no fluorescence at high concentrations but when there is fusion the membranes get mixed together and the dye gets diluted and fluoresces.
What changes in the body does the disease FHL4 cause?
- Over proliferation of T-Cells, natural killer cells, B-Cells and macrophages.
- Can also cause a cytokine storm (over-expression of cytokines)
What are some examples of clostridial neurotoxins ?
Clostridium tetani (Tetanus) & Clostridium botulinum (Botulism)
What does tetanus do to the body?
Causes powerful and uncontrollable muscle spasms.
What does botulism do to the body?
Causes the muscles to to relax at a dangerous rate “floppy baby syndrome”
What are the 3 domains of clostridial neurotoxins?
1- The targeting domain - binds to the neuron.
2- Translocation domain - allows entrance into the endosome by endocytosis.
3- Protease domain - cleaves to the SNARE molecules.
