Going 'Beyond the Genome'
14/10/10 14:08 Filed in: GenomeWeb Daily Scan
Submitted by S. Pelech - Kinexus on Thu, 10/14/2010 - 14:08.
It is intriguing that despite the complete sequencing of the human genome for many years now, it is still unresolved exactly how many human genes actually exist. Mass spectrometry studies have revealed several protein sequences that were not originally described in gene databases. In my own experience, with the assignment of over 90,000 phospho-sites in predicted human proteins for PhosphoNET (www.phosphonet.ca), I have noticed several hundred proteins that were originally documented in UniProt (www.uniprot.org) that have had the entries deleted without any replacements. Since these phosphoproteins were identified from cell lysates by mass spectrometry, obviously the encoding genes actually exist. Since Uniprot has just over 21,000 distinct human proteins currently listed, perhaps 4 to 5 percent of human proteins are still not tracked in the best repository that we have information about our proteins. How well the 22,333 figure for the total number of human genes accounts for these anomalies identified by mass spectrometry analysis of proteins is also unclear.
Link to the original blog post.
It is intriguing that despite the complete sequencing of the human genome for many years now, it is still unresolved exactly how many human genes actually exist. Mass spectrometry studies have revealed several protein sequences that were not originally described in gene databases. In my own experience, with the assignment of over 90,000 phospho-sites in predicted human proteins for PhosphoNET (www.phosphonet.ca), I have noticed several hundred proteins that were originally documented in UniProt (www.uniprot.org) that have had the entries deleted without any replacements. Since these phosphoproteins were identified from cell lysates by mass spectrometry, obviously the encoding genes actually exist. Since Uniprot has just over 21,000 distinct human proteins currently listed, perhaps 4 to 5 percent of human proteins are still not tracked in the best repository that we have information about our proteins. How well the 22,333 figure for the total number of human genes accounts for these anomalies identified by mass spectrometry analysis of proteins is also unclear.
Link to the original blog post.