Protein overexpression is a very common and widely used procedure. I am sharing an important artilcle and this will help you understanding the overexpression protocol in a comprehensive way.
You need to clone a cDNA of the gene directionally in an expression vector system specific to your cell line,,for e.g if you are working with mammallian cell lines,,,mammalian expression vector with CMV promoter works good....transfect the cell line with cDNA clone.... create a stable cell line using a selection marker system of the vector..