Triacylglycerol synthesis Flashcards
Kennedy pathway
Starting material is Glycerol-3-phosphate. GPAT adds first fatty acid from FA CoA. AGPAT uses FA CoA to add the second FA. PAP then removes the phosphate group and DGAT adds the last FA CoA to make triacylglycerol.
4 rxns
GPAT–>AGPAT–>PAP–>DGAT
Where are the substrates for TG synthesis coming from
Derived from glucose (glycolysis)
T/F fatty acids used to synthesize TG have to be bound to CoA to be activated
true
Which GPAT are in the mitochondria and which are in endoplasmic reticulum
GPAT1 and GPAT2 are in mitochondria
GPAT3/10 and GPAT4/6 in endoplasmic reticulum
Which GPAT is important for TG production
GPAT 3 and 4 because it they are found in adipose tissue
What do GPAT3 and 4 do
Produce 1-acylglycero-3-phosphate for TG biosynthesis. GPAT4 can compensate for GPAT3
How many AGPATs are there and which is the most used
AGPAT 2
what is Berardinelli-Seip Syndrom
human without AGPAT2
Lipodystrophic disease
inability to synthesize TG
No AGPAT activity even though AGPAT2 is the only one impaired
TG accumulates in the liver resulting in liver damage
lack adipose tissue
Free fatty acids get redirected to the liver
How can adipose tissue be visualized
MRI
What does Phosphatidate phosphohydrolase do
catalyzes phosphatidate to 1,2-diacylglycerol
removes phosphate group
What happens to DG and TG in yeast without Pah1P
DG and TG levels decrease
What are fld mice
fatty liver dystrophy. Has a spontaneous mutation that results in almost no TG. Insulin resistant. Hypertriglyceridemia
mutation in the lipin gene
is there a human version of Pah1
lipin
what is the function of Lipin
transcriptional coactivator
Works with other transcription factors to activate genes needed for FA oxidation
is also an enzyme and accounts for all PAP activity in adipose tissue
Where is lipin1,2,3 expressed
Lipin1 mainly in adipose
2 and 3 in liver not in adipose