title: Trans-splicing of an early embryo mRNA in Litomosoides carinii, coding for the major microfilarial sheath protein gp22.
abstract: Both genomic and cDNA clones have been isolated encoding the major sheath glycoprotein, gp22, of Litomosoides carinii microfilariae. The mature gp22 mRNA is shown to result from both trans-splicing of a 22-nucleotide 5'-leader sequence to an acceptor site at position 313 of the pre-mRNA, immediately upstream from the start codon, and from cis-splicing of a 117-nt intron located within the coding sequence. Cis-splicing precedes the trans-splicing reaction. The gp22 reading frame of 148 codons has the inferred structure of a prepro-protein and includes a leader peptide and a pro-segment ahead of the known N terminus of the mature, extracellular protein of 105 amino acids. The N-terminal part of that protein contains five repeats of an elastin-related pentapeptide sequence, which, together with a proline-threonine segment between two Cys clusters in the center and at its C terminus, may cause an elongated conformation with an apparent molecular size of 22 kDa in contrast to the calculated M(r) of 11,200.
authors.affiliation: Institut für Mikrobiologie und Molekularbiologie, Universität Giessen, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Christ
authors.forename: J
authors.initials: J
authors.lastname: Hirzmann
authors.forename: F
authors.initials: F
authors.lastname: Conraths
authors.forename: H
authors.initials: H
authors.lastname: Zahner
authors.forename: S
authors.initials: S
authors.lastname: Stirm
authors.forename: G
authors.initials: G
authors.lastname: Hobom
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D005370:Filarioidea / Q000235:genetics* / Q000254:growth & development; D015870:Gene Expression; D017238:Genes, Helminth; D006023:Glycoproteins / Q000235:genetics*; D015801:Helminth Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D011401:Promoter Regions, Genetic; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics; D011994:Recombinant Proteins
chemical_list: D006023:Glycoproteins; D015801:Helminth Proteins; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D011994:Recombinant Proteins; C078443:GP22 protein, Litomosoides carinii; D004247:DNA