title: An intercellular heme-trafficking protein delivers maternal heme to the embryo during development in C. elegans.
abstract: Extracellular free heme can intercalate into membranes and promote damage to cellular macromolecules. Thus it is likely that specific intercellular pathways exist for the directed transport, trafficking, and delivery of heme to cellular destinations, although none have been found to date. Here we show that Caenorhabditis elegans HRG-3 is required for the delivery of maternal heme to developing embryos. HRG-3 binds heme and is exclusively secreted by maternal intestinal cells into the interstitial fluid for transport of heme to extraintestinal cells, including oocytes. HRG-3 deficiency results either in death during embryogenesis or in developmental arrest immediately post-hatching-phenotypes that are fully suppressed by maternal but not zygotic hrg-3 expression. Our results establish a role for HRG-3 as an intercellular heme-trafficking protein.
authors.affiliation: Department of Animal & Avian Sciences and Department of Cell Biology & Molecular Genetics, University of Maryland, College Park, MD 20742, USA.
authors.forename: Caiyong
authors.initials: C
authors.lastname: Chen
authors.forename: Tamika K
authors.initials: TK
authors.lastname: Samuel
authors.forename: Jason
authors.initials: J
authors.lastname: Sinclair
authors.forename: Harry A
authors.initials: HA
authors.lastname: Dailey
authors.forename: Iqbal
authors.initials: I
authors.lastname: Hamza
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D006418:Heme / Q000172:deficiency / Q000378:metabolism*; D006420:Hemeproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000378:metabolism; D009154:Mutation; D010641:Phenotype; D021381:Protein Transport; D055571:Secretory Pathway
chemical_list: D006420:Hemeproteins; D006418:Heme