What is the difference between microRNAs with star and without star?

Question

[a511512345]

What is the difference between microRNAs with star and without star?

For example what's the difference between these 4 microRNAs? hsa-miR-101* hsa-miR-101 hsa-miR-101-3p hsa-miR-101-5p Which pairs (if) are the same? Which pairs are the same in sequence?

Answer 1

[Asaf]

miR-101 is the active miRNA, usually the 5p side. The star is the miRNA resulting from the other side of the hairpin, usually assumed to be non-active. This perspective has changed and now miRs are marked with 5p and 3p so usually hsa-miR-101 is hsa-miR-101-5p and hsa-miR-101* is hsa-miR-101-3p but you should check each case because sometimes the non-starred is the 3p.

[a511512345]

Thank you very much for your answer, which is great for me. I've got some differentially expressed miRNAs, how do i know if his active miRNA is 3p or 5p? When i want to predict his target gene, should i use 3p or 5p?

[Asaf]

You can refer to miRbase and look specifically on miR of interest

[a511512345]

For example, I would like to know whether the active form of hsa-miR-3613 is 5 or 3p? I went to miRbase view, found both forms have, I do not know which one is the active form? Can you teach me to distinguish? thank you very much

[Asaf]

In this specific case they might both be active since they both have comparable amount of sequencing reads. There isn't a lot of other data regarding this specific miRNA. In the case of hsa-mir-101-1 it's much easier to see that the 3p has a lot more reads than the 5p and probably is the active part.

[a511512345]

So I predict that the miR-3613 target gene should be the sum of the predicted 3p and 5p respectively? Because miRNA-name is only miRNA-3613 in TCGA. And no miRNA-3613-3p or miRNA-3613-5p

[Asaf]

I'm not familiar with TCGA data to answer this. Sorry

[a511512345]

thank you all the same, you have helped me a lot

Answer 2

[byun.seyoun]

I wonder have you figured that out? I have same problem that TCGA does not provide 3p or 5p information. That makes me very hard to find gene target. Because of that I have been also looking through isoform information. However, now I am having difficulties about the normalization all 3p information or all 5p information. Please let me know if you figured that out. Thank you