Identification and structural characterization of a cDNA clone encoding a membrane-bound form of the polypeptide pheromone Er-1 in the ciliate protozoan Euplotes raikovi.
In the ciliate Euplotes raikovi, the same cell that secretes the pheromone Er-1, a polypeptide of 40 amino acids derived from a precursor (prepro-Er-1) of 75 amino acids, also produces a polypeptide of 130 amino acids, of which the 75 residues at the carboxyl terminus are identical to those of prepro-Er-1 and the 55 residues at the amino terminus form a new sequence. This larger Er-1 isoform is retained in membranes, where it may function as a binding site for soluble Er-1 in a mechanism of autocrine secretion. Membrane-bound and soluble Er-1 are translated from two mRNAs that apparently originate from a common micronuclear and/or macronuclear gene through alternative elimination of intervening sequences. This finding suggests that single genes responsible for the generation of isoform diversity in polypeptide hormones are present even in single-celled eukaryotes.
Miceli
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Department of Molecular, Cellular, and Animal Biology, University of Camerino, Italy.
La Terza
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Bradshaw
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Luporini
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D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D016812:Euplotes / Q000235:genetics*; D015870:Gene Expression; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000276:immunology; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D010675:Pheromones / Q000235:genetics*; D016133:Polymerase Chain Reaction; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics*; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics; D012995:Solubility
D008565:Membrane Proteins; D009838:Oligodeoxyribonucleotides; D010675:Pheromones; D015800:Protozoan Proteins; D012333:RNA, Messenger; C057783:mating pheromone Er-1, Euplotes raikovi; D004247:DNA