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Two isotocin genes are present in the white sucker Catostomus commersoni both lacking introns in their protein coding regions.
Author(s) -
Figueroa J.,
Morley S.D.,
Heierhorst J.,
Krentler C.,
Lederis K.,
Richter D.
Publication year - 1989
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1989.tb08435.x
Subject(s) - biology
Two genes each encoding a distinct precursor protein to the hormone isotocin and a neurophysin‐related protein are present in the teleost fish Catostomus commersoni. These precursors are referred to as isotocin 1 and 2. As shown by the polymerase chain reaction technique, both genes lack introns in their protein‐coding sequences. Both genes are transcribed giving rise to mRNAs of 920 (isotocin 1) and 1020 (isotocin 2) bases, respectively. Based on the nucleotide sequences, the predicted isotocin precursors contain, besides the hormone moiety, a neurophysin‐like protein that, in contrast to its mammalian counterpart, is extended at its C‐terminus by a peptide which includes a leucine‐rich core segment. This segment shows similarities to the copeptin of the mammalian vasopressin precursor that is known to possess prolactin‐releasing activity. The data imply that the mammalian copeptin sequence was initially part of a larger ancestral neurophysin molecule.