title: Bioinformatic prediction of Trichoplax adhaerens regulatory peptides.
abstract: Trichoplax adhaerens (phylum Placozoa) is a very simple organism that lacks a nervous system. However, its genome contains many genes essential for neuronal function and development. I report the results of regulatory peptide predictions for this enigmatic animal. Extensive transcriptome, genome, and predicted proteome mining allowed us to predict four insulins, at least five short peptide precursors, one granulin, one paracrine regulator of cell growth, and one complex temptin-attractin pheromone signaling system. The expression of three insulins, four short peptide precursors, granulin, and one out of the six temptin genes was detected. Five predicted regulatory peptide precursors could potentially release over 60 different mature peptides. Some of the predicted peptides are somewhat similar to anthozoan RW amides, Aplysia pedal peptide 3, and PRQFV amide. Other predicted short peptides could not readily be classified into established families. These data provide the foundation for the molecular, biochemical, physiological, and behavioral studies of one the most primitive animal coordination systems, and give unique insight into the origins and early evolution of the nervous system.
authors.affiliation: Lomonosov Moscow State University, A.N. Belozersky Institute of Physico-chemical Biology, Leninskie Gory 1, Bldg. 40, Moscow 119991, Russia. Electronic address: nikitin.fbb@gmail.com.
authors.forename: Mikhail
authors.initials: M
authors.lastname: Nikitin
mesh_terms: D000577:Amides / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D005075:Biological Evolution; D019295:Computational Biology / Q000379:methods*; D016678:Genome; D061385:Insulins / Q000378:metabolism; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism; D010446:Peptide Fragments / Q000145:classification* / Q000235:genetics* / Q000378:metabolism; D054909:Placozoa / Q000235:genetics*; D020543:Proteome
chemical_list: D000577:Amides; D061385:Insulins; D009479:Neuropeptides; D010446:Peptide Fragments; D020543:Proteome
keywords: Neuronal precursors; Placozoa; T. adhaerens