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KEROCHI
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07/07/05 - 01:02 AM             #1

w/c of the ff. proceses allows apolipoprotein B to be synthesized in the liver as 100kDa protein & a 48kDa protein in the intestine?

A.RNA splicing

B. DNA rearrangement

C. proteolytic cleavage

D. phosphorylation

E. RNA editing


SDK
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07/07/05 - 01:24 AM             #2

It is E...RNA editing.....wink

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KEROCHI
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07/07/05 - 10:58 AM             #3

way to go SDK!

HighHopes
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09/19/05 - 08:41 PM             #4

SDK, Kerochi

Would you explain RNA Editing ?

Thanks






HighHopes
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09/19/05 - 08:41 PM             #5

SDK, Kerochi

Would you explain RNA Editing ?

Thanks






mildus
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09/20/05 - 02:23 AM             #6

You have a gene for apolipoprotein B and it is expressed in intestinal cells and in hepatocytes. By a process called transcription you get messenger RNA (mRNA). Then, mRNA can be used for translation so ApoB100 is made (in liver). But in intestines, before translation, there is mRNA editing which involves nucleotide modification by a specific enzyme. RNA editing changes a codon (CAA) in the middle of mRNA to a stop codon (UAA) so a smaller protein is made and that is why it is called ApoB48.




HighHopes
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09/20/05 - 07:14 AM             #7

Thanks mildus


mixo
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10/02/05 - 11:15 AM             #8

i'm interesting ..how i can use this info. in my practic?




mildus
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10/02/05 - 12:38 PM             #9

not much, mixo

gpsbrar
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10/02/05 - 01:56 PM             #10

Guys. Now I am scared. I didn't read this kind of question earlier. Man it is something very new detail. From where did you read about it. PLease share if you don't mind. Can they goto this much detail in USMLE. U guys are Genious. So much knowledge u have. I appreciate it that u share with everyone. Thanks.

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mildus
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10/04/05 - 12:38 AM             #11

Just type "RNA editing" on Google, and you will get some excellent web pages about that topic.
I think you can also find it in books about molecular biology or biochemistry.
RNA editing is just one of the ways of gene expression regulation and it is very rare.
I don't know if USMLE insists on such things.
No one knows everything, but the point is to look for, to search, in order to increase knowledge, and of course to share knowledge and not keep it just for oneself.


reet
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10/20/05 - 11:54 AM             #12

RNA edditing in intestines...ok does it occur anywhere else in body or not?????

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mildus
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10/23/05 - 04:00 AM             #13

I'm not sure. I know this process is very rare







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