QuestionSBA
QuestionChoice
Serine phosphorylation of Akt is performed by PDK-1 and mTORC2, activating its anabolic functions only when insulin is bound to the receptor and the cell is in an ATP-rich state.

<br>
10001110
e
Serine phosphorylation of Akt
QuestionChoice
Phospholipase C catalyses the hydrolysis of PIP3 to diacylglycerol (DAG). This activates PKC which phosphorylates intracellular targets to modulate cell activity, as well as inositol trisphosphate (IP3) which binds to IP3 receptors and allows for calcium efflux from the endoplasmic reticulum into the cytoplasm to modulate cell activity.
10001107
b
Hydrolysis of PIP3 to IP3 and DAG
QuestionChoice
This is the description of a guanine nucleotide exchange factor such as a G-protein coupled receptor. An example of a G-protein coupled receptor is the a1 adrenoceptor which accelerates GDP release from Ga-q type G-proteins to allow GTP entry and the activation of G-protein function.
10001109
d
Exchange of GDP for GTP in G-proteins
QuestionChoice
Phosphoinositide-3-kinase (PI3K) phosphorylates PIP2 to PIP3 on the inner side of the plasma membrane. This acts as a scaffold for the pleckstrin homology domain of Akt which phosphorylates targets including FOXO1, mTOR, glycogen synthase kinase and components of the GLUT4 exocytosis pathway. Together, this promotes protein synthesis, inhibits gluconeogenesis, promotes glycogenesis and promotes glucose uptake into cells.
10001106
a
Phosphorylation of PIP2 to PIP3
QuestionChoice
Upon binding of insulin to the external domains of the constitutively hetero-tetrameric insulin receptor, the tyrosine-rich cytoplasmic domains change conformation, allowing for the trans-phosphorylation of the tyrosine residues on each domain. This creates a scaffold for the SH3 domains of substrates to bind to and initiate downstream signalling.
10001108
c
Tyrosine phosphorylation of the insulin receptor
Concept
Chapter
2693
3884
Cell signalling
Topic
181
Structure and Function of Cells
12768
Which reaction does PI3K catalyse (upon activation) downstream of the insulin receptor?
a