Number of proteins expressed in cell
Posted 29 April 2010 - 02:18 PM
Does anyone know how many different proteins are expressed in a mammalian cell?
I know there is supposed to be between 10 - 20 thousand but can anyone give me a reference for this?
Has there been a proteomic study done to answer this question?
Posted 29 April 2010 - 04:18 PM
Posted 29 April 2010 - 07:27 PM
Although the DNA genome that is within the nucleus of each human cell is estimated to encode for >30,000 proteins, only a fraction of these proteins are expressed in each cell type and it is this differential level of protein expression which largely accounts for the difference between, for instance, a skin cell versus a liver cell. Within a given cell different proteins vary widely in their level of expression - with some regulatory proteins being present in perhaps only a few copies while other proteins (e.g. those found in muscles) may be present in as many as millions of copies/cell.
From Background Information on the Human Proteome and the Yale/NHLBI Proteomics Center.
The fact is, we just don't know how many proteins comprise the human proteome -- a project to find out was started last year (see here).