par Cohick, C B;Dai, G;Xu, L;Deb, S;Kamei, T;Levan, Göran;Szpirer, Claude 
;Szpirer, Josiane ;Kwok, S C;Soares, M J
Référence Molecular and cellular endocrinology, 116, 1, page (49-58)
Publication Publié, 1996-01
;Szpirer, Josiane ;Kwok, S C;Soares, M JRéférence Molecular and cellular endocrinology, 116, 1, page (49-58)
Publication Publié, 1996-01
Article révisé par les pairs
| Résumé : | Placenta lactogen-I variant (PL-Iv) is a member of a family of proteins expressed by the rat placenta with characteristics similar to prolactin (PRL). In this report, we present the molecular cloning, chromosomal localization, and heterologous expression of PL-Iv. Nucleotide sequence analysis of the PL-Iv cDNA clone predicted a precursor protein of 223 amino acids, including a 28-amino acid signal sequence. The PL-Iv gene was localized to chromosome 17 of the rat genome, which also carries other members of the PRL gene family. PL-Iv heterologously expressed in Chinese Hamster ovary (CHO) cells exhibited similar immunoreactive and electrophoretic characteristics with PL-Iv produced by the rat placenta. N-terminal sequencing verified the identity and purity of the recombinant PL-Iv species and the site of cleavage of the signal peptide from the mature secreted PL-Iv species. Recombinant PL-Iv was shown to bind to ovarian and liver PRL receptors, stimulate the proliferation of Nb2 lymphoma cells, and activate Jak2. Each of these actions is consistent with PL-Iv utilizing the PRL receptor signal transduction pathway. |
