How many different proteins are there in the Human body?
The human proteome is much larger than the genome due to alternative splicing. Current thought is that some 40 – 60% of human genes have alternative splicing isoforms. Large-scale studies on chromosomes 21 and 22 indicate that over 80% of the genes could undergo alternative splicing. It is currently estimated at about 90,000 proteins are possible from the 23,000-25,000 genes. Many of these are subunits that can be combined in multiple protein complexes that further extend the range of the proteome. Many proteins are modified in a cell specific manner after they are translated. These modifications allow the same gene product a range of protein functions.
