All mRNA translated into protein - (May/18/2012 )

Am I correct to say that all mRNA will be translated into protein provided they have the 5' cap and Poly-A tails? Or what is the best reason to support that all mRNA translated into protein?

From what i think is:
- The cells wont waste energy if they transcribed mRNA but not translated into protein.


Can anyone enlighten me?

Not entirely true, there are many mRNAs that do not have poly A tails. There is also evidence that the cell can hold some mRNA in a pool for later use, especially for stress response proteins IIRC.

Here's an article on nonsense mediated decay and the pioneer round of translation: http://www.sciencedirect.com/science/article/pii/S0092867410008263
Cells often will make mRNAs with premature stop codons which need to be destoyed. Of course the pioneer round of translation will have made a truncated peptide, so technically translation has occurred, but no full length protein was produced, hence net waste of energy.