Molecular cloning and characterization of pirarucu (Arapaima gigas) follicle-stimulating hormone and luteinizing hormone ?-subunit cDNAs.

ABSTRACT: The common gonadotrophic hormone ?-subunit (GTH?) has been previously isolated by our research group from A. gigas pituitaries; in the present work the cDNA sequences encoding FSH? and LH? subunits have also been isolated from the same species of fish. The FSH ?-subunit consists of 126 amino acids with a putative 18 amino acid signal peptide and a 108 amino acid mature peptide, while the LH ?-subunit consists of 141 amino acids with a putative 24 amino acid amino acid signal peptide and a 117 amino acid mature peptide. The highest identity, based on the amino acid sequences, was found with the order of Anguilliformes (61%) for FSH? and of Cypriniformes (76%) for LH?, followed by Siluriformes, 53% for FSH? and 75% for LH?. Interestingly, the identity with the corresponding human amino acid sequences was still remarkable: 45.1% for FSH? and 51.4% for LH?. Three dimensional models of ag-FSH and ag-LH, generated by using the crystal structures of h-FSH and h-LH as the respective templates and carried out via comparative modeling and molecular dynamics simulations, suggested the presence of the so-called "seat-belt", favored by a disulfide bond formed between the 3rd and 12th cysteine in both ?-subunits. The sequences found will be used for the biotechnological synthesis of A. gigas gonadotrophic hormones (ag-FSH and ag-LH). In a first approach, to ascertain that the cloned transcripts allow the expression of the heterodimeric hormones, ag-FSH has been synthesized in human embryonic kidney 293 (HEK293) cells, preliminarily purified and characterized.

SUBMITTER: Sevilhano T 

PROVIDER: S-EPMC5573580 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature