title: Structural and functional diversity of nonapeptide hormones from an evolutionary perspective: A review.
abstract: The article presents an overview of the comparative distribution, structure and functions of the nonapeptide hormones in chordates and non chordates. The review begins with a historical preview of the advent of the concept of neurosecretion and birth of neuroendocrine science, pioneered by the works of E. Scharrer and W. Bargmann. The sections which follow discuss different vertebrate nonapeptides, their distribution, comparison, precursor gene structures and processing, highlighting the major differences in these aspects amidst the conserved features across vertebrates. The vast literature on the anatomical characteristics of the nonapeptide secreting nuclei in the brain and their projections was briefly reviewed in a comparative framework. Recent knowledge on the nonapeptide hormone receptors and their intracellular signaling pathways is discussed and few grey areas which require deeper studies are identified. The sections on the functions and regulation of nonapeptides summarize the huge and ever increasing literature that is available in these areas. The nonapeptides emerge as key homeostatic molecules with complex regulation and several synergistic partners. Lastly, an update of the nonapeptides in non chordates with respect to distribution, site of synthesis, functions and receptors, dealt separately for each phylum, is presented. The non chordate nonapeptides share many similarities with their counterparts in vertebrates, pointing the system to have an ancient origin and to be an important substrate for changes during adaptive evolution. The article concludes projecting the nonapeptides as one of the very first common molecules of the primitive nervous and endocrine systems, which have been retained to maintain homeostatic functions in metazoans; some of which are conserved across the animal kingdom and some are specialized in a group/lineage-specific manner.
authors.affiliation: Department of Zoology, Centre of Advanced Study, Banaras Hindu University, Varanasi 221005, India.
authors.forename: P
authors.initials: P
authors.lastname: Banerjee
authors.affiliation: Department of Biotechnology, Cochin University of Science and Technology, Kochi 682022, India. Electronic address: kpjoybhu@gmail.com.
authors.forename: K P
authors.initials: KP
authors.lastname: Joy
authors.affiliation: Department of Zoology, Centre of Advanced Study, Banaras Hindu University, Varanasi 221005, India.
authors.forename: R
authors.initials: R
authors.lastname: Chaube
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001921:Brain / Q000378:metabolism; D006801:Humans; D009490:Neurosecretory Systems / Q000378:metabolism; D009842:Oligopeptides / Q000737:chemistry* / Q000502:physiology*; D010121:Oxytocin / Q000737:chemistry / Q000502:physiology; D036361:Peptide Hormones / Q000737:chemistry* / Q000502:physiology*; D013329:Structure-Activity Relationship; D014714:Vertebrates / Q000235:genetics / Q000378:metabolism
chemical_list: D009842:Oligopeptides; D036361:Peptide Hormones; D010121:Oxytocin
keywords: Evolutionarily conserved; Functional diversity; Nonapeptides; Oxytocin/vasopressin superfamily; Structural diversity