Lecture 10

Question 1

Enzymes in 5’ cap addition

Answer 1

Phosphatase: remove gamma P
Guanyl transmethyl transferase: add GMP
Guanine-7-methyl transferase: add methyl to N7
Some:
2’-O-methyl transferase: add methyl to C2 of first ribose

Question 2

ADAR = adenosine deaminase acting upon RNA enzyme mechanism

Answer 2

Complementary exon and intron form dsRNA

ADAR target and modify adenosine to inosine

Question 3

3 types of ADAR

Answer 3

ADAR1: liver, erythrocyte development
ADAR2: brain
ADAR3: ?

Question 4

A-I editing in glutamate receptor mRNA in brain

Answer 4

W/o editing: glutamine, in response to Glu, conduct both Na+ and Ca2+
W/ editing: arginine, in response to glu, conduct only Na+

Question 5

C-U editing protein and results

Answer 5

By cytidine deaminase
Full length in liver w/o editing
Truncated protein in intestine coz editing gives a stop codon

Question 6

Systemic lupus erythematosis

Answer 6

Auto-antibodies react with U1 RNA of spliceosome

Prevents normal RNA editing