title: Plant natriuretic peptides: systemic regulators of plant homeostasis and defense that can affect cardiomyoblasts.
abstract: Immunologic evidence has suggested the presence of biologically active natriuretic peptide (NPs) hormones in plants because antiatrial NP antibodies affinity purify biologically active plant NPs (PNP). In the model plant, an Arabidopsis thaliana PNP (AtPNP-A) has been identified and characterized. AtPNP-A belongs to a novel class of molecules that share some similarity with the cell wall loosening expansins but do not contain the carbohydrate-binding wall anchor thus suggesting that PNPs and atrial natriuretic peptides are heterologs. AtPNP-A acts systemically, and this is consistent with its localization in the apoplastic extracellular space and the conductive tissue. Furthermore, AtPNP-A signals via the second messenger cyclic guanosine 3',5'-monophosphate and modulates ion and water transport and homeostasis. It also plays a critical role in host defense against pathogens. AtPNP-A can be classified as novel paracrine plant hormone because it is secreted into the apoplastic space in response to stress and can enhance its own expression. Interestingly, purified recombinant PNP induces apoptosis in a dose-dependent manner and was most effective on cardiac myoblast cell lines. Because PNP is mimicking the effect of ANP in some instances, PNP may prove to provide useful leads for development of novel therapeutic NPs.
authors.affiliation: Division of Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia. christoph.gehring@KAUST.edu.sa
authors.forename: Chris
authors.initials: C
authors.lastname: Gehring
authors.forename: Helen
authors.initials: H
authors.lastname: Irving
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017360:Arabidopsis / Q000378:metabolism; D006706:Homeostasis / Q000187:drug effects*; D006801:Humans; D008969:Molecular Sequence Data; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000378:metabolism*; D045265:Natriuretic Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D057865:Plant Immunity / Q000187:drug effects*; D010944:Plants / Q000378:metabolism*
chemical_list: D045265:Natriuretic Peptides