title: Extra-mitochondrial localization and likely reproductive function of a female-transmitted cytochrome c oxidase subunit II protein.
abstract: Our previous study documented a reproductive function for the male-transmitted mitochondrial DNA (mtDNA)-encoded cytochrome c oxidase subunit II (MCOX2) protein in a unionoid bivalve. Here, immunoblotting, immunohistochemistry and immunoelectron microscopy analyses demonstrate that the female-transmitted protein (FCOX2) is: (i) expressed in both male and female gonads; (ii) maximally expressed in ovaries just prior to the time of the annual fertilization event; (iii) displayed in the cytoplasm and more strongly in the plasma membrane (microvilli), vitelline matrix and vitelline envelope of mature ovarian eggs; and (iv) strongly localized to the vitelline matrix of some eggs just prior to fertilization. These findings represent evidence for the extra-mitochondrial localization of an mtDNA-encoded gene product and are consistent with multifunctionality for FCOX2 in eggs.
authors.affiliation: Department of Biochemistry, State University of New York, Buffalo, New York 14214, USA. rumela.chakrabarti@gmail.com
authors.forename: Rumela
authors.initials: R
authors.lastname: Chakrabarti
authors.forename: Sally
authors.initials: S
authors.lastname: Shepardson
authors.forename: Moumita
authors.initials: M
authors.lastname: Karmakar
authors.forename: Richard
authors.initials: R
authors.lastname: Trdan
authors.forename: Jennifer
authors.initials: J
authors.lastname: Walker
authors.forename: Ramdas
authors.initials: R
authors.lastname: Shandilya
authors.forename: Don
authors.initials: D
authors.lastname: Stewart
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Vijayaraghavan
authors.forename: Walter
authors.initials: W
authors.lastname: Hoeh
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D004272:DNA, Mitochondrial / Q000235:genetics / Q000502:physiology*; D003576:Electron Transport Complex IV / Q000378:metabolism / Q000502:physiology*; D005260:Female; D005786:Gene Expression Regulation / Q000235:genetics / Q000502:physiology; D006066:Gonads / Q000378:metabolism / Q000648:ultrastructure; D015151:Immunoblotting; D007150:Immunohistochemistry; D008297:Male; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D010063:Ovum / Q000378:metabolism / Q000648:ultrastructure; D012098:Reproduction / Q000235:genetics / Q000502:physiology*; D012621:Seasons; D049876:Unionidae / Q000201:enzymology* / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D004272:DNA, Mitochondrial; C117108:cytochrome C oxidase subunit II; D003576:Electron Transport Complex IV