Changes in post-translational modifications of prolactin during development and reproductive cycles in the chicken.
Changes in proportion of glycosylated prolactin in the anterior pituitary glands of chickens were assessed using one- and two-dimensional western blotting analysis during the perihatch stage of embryos and reproductive cycles. Multiple isoforms of prolactin were detected by one-dimensional analysis and glycosylated (G) and non-glycosylated (NG) isoforms were identified by N-glycosidase and neuraminidase treatment. Increases of ratio of G to NG isoforms were observed in both embryonic stages and reproductive cycles by the one-dimensional analysis. Although a similar tendency of increase of proportion of G prolactin was obtained, different values of proportion were observed between one-dimensional and two-dimensional analysis. Since two-dimensional analysis may better resolve isoforms differing slightly in molecular size of G prolactin, the results from two-dimensional analysis may reflect the actual proportion of prolactin isoforms. Furthermore, isoforms differing in isoelectric points were detected after N-glycosidase and neuraminidase treatment. These results indicate that prolactin may also be additionally post-translationally modified such as by phosphorylation. Thus function and biological activity of prolactin were, at least in part, regulated by post-translational modification in the various physiological stages.
Hiyama
Gen
G
Laboratory of Animal Genetics and Breeding, Azabu University, Fuchinobe, Sagamihara, Japan.
Kansaku
Norio
N
Kinoshita
Mihoko
M
Sasanami
Tomohiro
T
Nakamura
Akihiro
A
Noda
Kenji
K
Tsukada
Akira
A
Shimada
Kiyoshi
K
Zadworny
David
D
D000818:Animals; D015153:Blotting, Western; D002642:Chick Embryo; D002645:Chickens / Q000254:growth & development / Q000502:physiology*; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D006031:Glycosylation; D010903:Pituitary Gland, Anterior / Q000378:metabolism; D011388:Prolactin / Q000031:analogs & derivatives / Q000378:metabolism*; D020033:Protein Isoforms / Q000378:metabolism; D011499:Protein Processing, Post-Translational / Q000502:physiology*; D011863:Radioimmunoassay
D020033:Protein Isoforms; C043928:prolactin, glycosylated; D011388:Prolactin