s****6
发帖数: 34 | 1 Someone overexpressed a certain microRNA in a cancer cell line and then
compared the mRNA profiles of control cells vs microRNA overexpressed cells.
It seems very obvious that a bounch of genes from a certain chromsome
location were all elevated at mRNA level. Those genes are also functionally
related too, but none of them is among the predicted targets of this microRNA
according to the results from all the popular bioinformatical web-tools. What could be the mechanism underneath? What should be done to figure out the connection? Your pointers would be highly appreciated. |
a****o
发帖数: 1786 | 2 This could be due to indirect effect. e.g.these genes are all negatively
regulated by a repressor X, X is the target of the microRNA. overexpresseion
of the microRNA, downregulated X and derepress the expression of that group
of genes. |
s****6
发帖数: 34 | 3 Thanks!! The trouble is that repressor X didn't show itself up in the
profiling data, i.e. none of the decreased mRNA seems to be such a repressor
and a direct target of that microRNA. No direct "targets" was ever found in
the profiling data...but those increased and decreased were indeed
confirmed with qPCR.
Could microRNAs alter gene expression via a mechanism that is not Waston-
Crick base-paring based?
Could microRNAs directly interact with protein factors or anything in the
transcriptional machine? How to prove or disprove this possibility?
overexpresseion
group
【在 a****o 的大作中提到】
: This could be due to indirect effect. e.g.these genes are all negatively
: regulated by a repressor X, X is the target of the microRNA. overexpresseion
: of the microRNA, downregulated X and derepress the expression of that group
: of genes.
|
a****o
发帖数: 1786 | 4 It may have additional repressor Y not identified yet.
repressor
in
【在 s****6 的大作中提到】
: Thanks!! The trouble is that repressor X didn't show itself up in the
: profiling data, i.e. none of the decreased mRNA seems to be such a repressor
: and a direct target of that microRNA. No direct "targets" was ever found in
: the profiling data...but those increased and decreased were indeed
: confirmed with qPCR.
: Could microRNAs alter gene expression via a mechanism that is not Waston-
: Crick base-paring based?
: Could microRNAs directly interact with protein factors or anything in the
: transcriptional machine? How to prove or disprove this possibility?
:
|
n******u
发帖数: 418 | 5 how about target genes mRNA of this microRNA? |
m*********n
发帖数: 56 | 6 It has also been reported that certain miRNA binds to 5'UTR or coding seq to
activate gene expression (see example: Vasudevan, S., Tong, Y. and Steitz,
J.A. (2007). Switching between repression and activation: microRNAs can
activate translation. Science. 318: 1931-1934. ).
Just throw out possibilities. |
s****6
发帖数: 34 | 7 any other possible explanations?
thanks! |
