Amino acids in the amino terminal region of the rat prolactin contribute to PRL-receptor binding and NB2 cell proliferation activity.
To elucidate the structure-function relationship of rat prolactin, seven conserved or semi-conserved amino acids in the amino terminal region were investigated by site-directed mutagenesis. The antigenicity and electrophoretic mobility, as well as receptor binding and Nb2 cell proliferation in various mutants were assayed. Mutants with the cysteine at position 9 replaced with glycine (C9G), as well as R19G, S24A, Y26S, Y42F and Y42S, decreased the activities of receptor binding and Nb2 cell proliferation. A mutation of residue at 42 resulted in a loss of most of the activities. A mutation of residue at 39 (D39V and D39G) increased both receptor binding and cell proliferation activities. Thus, this study demonstrated that the seven amino acids in the amino terminal region contribute to the biological function of rat prolactin and that tyrosine at 42 is especially important.
Maruyama
O
O
Biosignal Research Center, Gunma University, Japan.
Kato
T
T
Wakabayashi
K
K
Kato
Y
Y
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D002455:Cell Division; D005260:Female; D006801:Humans; D008969:Molecular Sequence Data; D011247:Pregnancy; D011388:Prolactin / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D051381:Rats; D011981:Receptors, Prolactin / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014407:Tumor Cells, Cultured
D000596:Amino Acids; D011981:Receptors, Prolactin; D011388:Prolactin