Characterization of the epidermal growth factor receptor in preimplantation pig conceptuses.
Embryos recovered from sows on Days 9-13 of pregnancy (Day 0 = first day of estrus) exhibited saturable and time-dependent specific binding of 125I-epidermal growth factor (EGF). The specific binding (pg/mg protein) was greater (P less than 0.001) for Day 13 elongated conceptuses than for conceptuses of earlier stages. Scatchard analyses showed two classes of binding sites (Kd = 7.0 +/- 2.6 x 10(-11) M, Bmax = 6.2 +/- 1.4 fmol/mg protein and Kd = 3.4 +/- 0.2 x 10(-8) M, Bmax = 420 +/- 80 fmol/mg protein). The EGF receptor in Day 13 conceptus membranes is a 170-kDa protein and was phosphorylated in the presence of EGF and adenosine triphosphate. EGF stimulated protein tyrosine kinase activity about 1.6-fold over basal levels. The results show that the preimplantation pig conceptus possesses EGF-binding sites with the properties of functional EGF-receptors.
Zhang
Y
Y
Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506.
Paria
B C
BC
Dey
S K
SK
Davis
D L
DL
D000595:Amino Acid Sequence; D000818:Animals; D001667:Binding, Competitive; D001755:Blastocyst / Q000378:metabolism*; D003432:Cross-Linking Reagents; D047108:Embryonic Development; D004789:Enzyme Activation / Q000187:drug effects; D066246:ErbB Receptors / Q000378:metabolism* / Q000502:physiology; D005260:Female; D005865:Gestational Age; D008969:Molecular Sequence Data; D011247:Pregnancy; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D013552:Swine / Q000196:embryology*
D003432:Cross-Linking Reagents; D066246:ErbB Receptors; D011505:Protein-Tyrosine Kinases