title: Evolution of alternative splicing: deletions, insertions and origin of functional parts of proteins from intron sequences.
abstract: Alternative splicing is thought to be a major source of functional diversity in animal proteins. We analyzed the evolutionary conservation of proteins encoded by alternatively spliced genes and predicted the ancestral state for 73 cases of alternative splicing (25 insertions and 48 deletions). The amino acid sequences of most of the inserts in proteins produced by alternative splicing are as conserved as the surrounding sequences. Thus, alternative splicing often creates novel isoforms by the insertion of new, functional protein sequences that probably originated from noncoding sequences of introns.
authors.affiliation: National Center for Biotechnology Information, National Institutes of Health, Bethesda, MD 20894, USA. fkondras@ncbi.nlm.nih.gov
authors.forename: Fyodor A
authors.initials: FA
authors.lastname: Kondrashov
authors.forename: Eugene V
authors.initials: EV
authors.lastname: Koonin
mesh_terms: D017398:Alternative Splicing / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence; D019143:Evolution, Molecular; D006801:Humans; D007438:Introns; D008957:Models, Genetic; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid
chemical_list: D020033:Protein Isoforms; D011506:Proteins