115 kDa protein from Xenopus laevis embryos recognized by antibodies directed against the Xenopus homeoprotein XIHbox 1.
Using antibodies against homeoprotein XIHbox 1 from Xenopus laevis, we have detected a new embryonic protein with a much larger molecular weight, 115 kDa. Antibodies fractionated according to their affinity for 3 different domains of the XIHbox 1 protein were used to show that this new protein is related to the C-terminal region of XIHbox 1 protein, downstream from the homeodomain. By immunohistochemistry, the protein was shown to be localized in nuclei of embryonic cells. On SDS-polyacrylamide gels, the 115 kDa protein appears as a set of closely spaced bands whose pattern varies with the stage of development and with the parental origin of the embryos. The protein could be extracted from embryos in a multiprotein complex of approximately 600 kDa. In contrast, the 18 and 27 kDa proteins predicted from the sequence of cloned cDNA to be transcribed and translated from the XIHbox 1 gene could not be detected, suggesting that they are rare or unstable in embryos. These data suggest that the new protein is involved in the development of Xenopus embryos, with a function possibly related to that of the homeoprotein XIHbox 1.
Flavin
M
M
Institut Jacques Monod, Paris, France.
Saint-Jeannet
J P
JP
Duprat
A M
AM
Strauss
F
F
D000818:Animals; D000906:Antibodies; D000918:Antibody Specificity; D015153:Blotting, Western; D004625:Embryo, Nonmammalian / Q000737:chemistry* / Q000648:ultrastructure; D018398:Homeodomain Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D007150:Immunohistochemistry; D008970:Molecular Weight; D011506:Proteins / Q000032:analysis* / Q000737:chemistry; D029867:Xenopus Proteins; D014982:Xenopus laevis / Q000196:embryology*
D000906:Antibodies; D018398:Homeodomain Proteins; C080041:Hoxc6 protein, mouse; D011506:Proteins; D029867:Xenopus Proteins; C489819:XlHbox-1 protein, Xenopus