Mutant isoforms of the anti-Müllerian hormone type II receptor are not expressed at the cell membrane.
Anti-Müllerian hormone, a member of the transforming growth factor beta superfamily, produces early regression of Müllerian ducts in the male fetus through binding to a serine/threonine kinase receptor, homologous to type II receptors of the transforming growth factor beta (TGF-beta) family. A splice mutation of this receptor, described in a patient with abnormal retention of Müllerian derivatives, generates two mutant isoforms, one lacking the second exon and the other bearing an insertion of 12 bases between exons 2 and 3. Using hemagglutinin-tagged recombinant receptors, we have visualized wild type and mutant receptors in COS cells by Western blotting and immunoprecipitation. The 82-kDa, endoglycosidase H-insensitive, mature form of the wild type receptor is reduced to 68 kDa by N-glycosidase F treatment. Mutant receptor isoforms, 73 and 63 kDa for the long and short form, respectively, are sensitive to endoglycosidase H, suggesting that they are retained in the endoplasmic reticulum. Indeed, only the wild type receptor was expressed on the cell surface and bound iodinated anti-Müllerian hormone. These results provide a biological explanation for the failure of the mutant receptor to induce Müllerian regression.
Faure
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Unité de Recherches sur l'Endocrinologie du Développement (INSERM), Ecole Normale Supérieure, Département de Biologie, 1 rue Maurice-Arnoux, 92120 Montrouge, France. clemente@wotan.ens.fr
Gouédard
L
L
Imbeaud
S
S
Cate
R
R
Picard
J Y
JY
Josso
N
N
di Clemente
N
N
D017398:Alternative Splicing; D000818:Animals; D019556:COS Cells; D002451:Cell Compartmentation; D002462:Cell Membrane / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D017354:Point Mutation; D018000:Receptors, Peptide / Q000235:genetics / Q000378:metabolism*; D018125:Receptors, Transforming Growth Factor beta; D013329:Structure-Activity Relationship
D008562:Membrane Glycoproteins; D018000:Receptors, Peptide; D018125:Receptors, Transforming Growth Factor beta; C084621:anti-Mullerian hormone receptor