title: A novel Cryptosporidium parvum antigen, CP2, preferentially associates with membranous structures.
abstract: The present study addresses the cloning and characterization of a Cryptosporidium parvum antigen, CP2. Sequencing of cDNA and genomic clones revealed a novel gene capable of coding a message of 2,136 nucleotides flanked by 28 and 140 nucleotides of the 5'- and 3'-noncoding regions, respectively. The deduced amino acid sequence suggests that CP2 is a secreted and/or membrane protein. Immunofluorescence microscopy detected CP2 enrichment in sporozoites that subsequently appeared to encase type I meronts in infected HCT-8 cells. Immunogold electron microscopy revealed that CP2 consistently localized to membranous structures throughout development. In addition, progression from macrogametocyte to sporulated oocyst revealed CP2 initially at the periphery of amylopectin-like granules, in the cytoplasm and discrete vesicles, the parasitophorous vacuole, on the surface of sporozoites, and finally on the parasitophorous vacuole membrane (PVM). The observed expression pattern suggests that CP2 may be involved in the invasion process and/or PVM integrity.
authors.affiliation: Department of Biological Sciences, University of Iowa, 138 Biology Building, Iowa City, IA 52242-1324, USA.
authors.forename: Steven P
authors.initials: SP
authors.lastname: O'Hara
authors.forename: Jae-Ran
authors.initials: JR
authors.lastname: Yu
authors.forename: Jim Jung-Ching
authors.initials: JJ
authors.lastname: Lin
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D000954:Antigens, Surface / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D016785:Cryptosporidium parvum / Q000235:genetics* / Q000254:growth & development / Q000276:immunology* / Q000378:metabolism; D016054:DNA, Protozoan / Q000737:chemistry / Q000302:isolation & purification; D017125:Genes, Protozoan; D006031:Glycosylation; D006801:Humans; D008856:Microscopy, Fluorescence; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D021382:Protein Sorting Signals; D024363:Transcription Initiation Site; D014617:Vacuoles / Q000378:metabolism*
chemical_list: D000953:Antigens, Protozoan; D000954:Antigens, Surface; D016054:DNA, Protozoan; D021382:Protein Sorting Signals