Hello Vandhana,

I have some working experience in Polysome analysis in Huh7 and HeLa cells. But I could not get your query properly. can you elaborate a little more on the problem?

In our experiments we too got small RNAs in the initial fractions, which gradually decreased towards the polysome fractions. Since we were looking at a viral RNA then, we did not check whether the small RNA fractions contained U1 or not. Please see the Figure 5.B of the attached paper.

best wishes,

SD

thanks for your help. U1snRNA is known to be associated with nucleus and is not known to be translated. So when I subject the cytoplasmic content isolated from HEK to ultracentrifugation and then isolate RNA from the pellleted polysomes and score for U1snRNA, am getting a positive signal. Theoretically I don't understand how this is possible. U1snRNA should be in nucleus and shouldn't come along with polysomes right?

Dr Vandhana,

I got your query now. I am attaching some papers, which might explain your observation of U1 snRNA in cytoplasm/polyribosome fractions.

Alternatively, as you have mentioned that the U1 snRNA is nuclear in location, you may also expect that the source of U1 in your polysome fractions might be the result of contamination of your cytoplasmic RNA prepparations with nuclear RNA. 

Best wishes,

SD