gene expression vs protein expression - (Oct/15/2005 )
Hi,
It is possible to have high levels of gene expression at the mRNA level and no change in expression at the protein level, right? But it is not possible to have high levels of protein expression and no change in gene expression at the mRNA level right?
how to find out if the dysregulated expression is to posttranscriptional or post translational modification?
I'm not an expert, but check the mRNA level of your gene of interest with Real Time-RT-PCR. And check the protein expression level with a western blot? I don't think the last one is really that sensitive to quantify, but you probably can tell wether you have higher or lower expression levels (I haven't performed any wester myself, but it just seems that way to me).
It is possible to have high levels of gene expression at the mRNA level and no change in expression at the protein level, right? But it is not possible to have high levels of protein expression and no change in gene expression at the mRNA level right?
how to find out if the dysregulated expression is to posttranscriptional or post translational modification?
It is very well possible to have increased protein levels without increased mRNA levels. Nice examples are the p53 protein (stabilisation in response to DNA damage) and Hif1 alpha protein (stabilisation in response to hypoxia).
And ofcourse, expression of some proteins is regulated on the level of translation (e.g. ATF4 in response to ER-stress) or at the level of splicing (e.g. XBP-1 in response to Ire1 activation).