contact membrane sites

Question 1

what is the Sarcoplasmic reticulum

Answer 1

Specialised ER for handling Ca2+ transients required for muscle contraction

Question 2

what is Stim1

Answer 2

Stim 1 is a calcium sensor in the ER

Question 3

What are Phosphoinositides

Answer 3

are a family of minority acidic phospholipids in cell membranes.

role is instructional: they interact with proteins.

Each cellular membrane compartment uses a characteristic species of phosphoinositide.

Question 4

what are 3 features of ER contact sites

Answer 4

Structure of ER contact sites:
° ribosomes excluded from contact sites
° membranes very close (3-15nm)
° ER contacts are long lived

Question 5

name 3 functions of the ER membrane sites

Answer 5

Functions: provide platforms for
° calcium mobilisation
° lipid transfer
° signalling

Question 6

what is special about MCS protein components

Answer 6

often extended to allow bridging between membranes Have to cross the 3-15nm gap

Question 7

what is CLEM

Answer 7

CLEM: correlative light and electron microscopy

allows localisation of fluorescently labelled proteins to MCS

Question 8

features of lipid transfer

Answer 8

ER: Site of Membrane lipid synthesis

Contact sites: Non vesicular transfer of lipid

Lipid transfer is unidirectional

Question 9

what is Niemann Pick Disease C

Answer 9

rare progressive genetic disorder characterized by an inability of the body to transport cholesterol and other fatty substances (lipids) inside of cells. This leads to the abnormal accumulation of these substances within various tissues of the body, including brain tissue

Question 10

What are NPC1+2

Answer 10

Protein that helps facilitate the transfer of lipids from endosome and lysosome to ER

Question 11

How are membrane contact sites are involved in organelle fission

Answer 11

ER tubules wind around the mitochondria causing it to pinch - fission