A gradient of BMP activity specifies dorsal-ventral fates in early Xenopus embryos.
BMP-4 is an extracellular signalling molecule belonging to the TGF-beta superfamily that plays a central role in dorsoventral patterning in vertebrate gastrulae. We review the evidence indicating that BMP-4 acts as a morphogen, specifying dorsoventral positional values in a concentration-dependent manner. An activity gradient of BMP-4 is established not by simple diffusion from a localised source, but by diffusion of inhibitory binding proteins that act on a uniform level of BMP-4 protein. These in turn are regulated by the activity of tolloid-related metalloproteases, such as Xenopus xolloid and zebrafish tolloid.
Dale
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Department of Anatomy and Developmental Biology, University College London, Gower Street, London, WC1E 6BT, UK.
Wardle
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FC
D000818:Animals; D019521:Body Patterning / Q000187:drug effects / Q000502:physiology*; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins / Q000037:antagonists & inhibitors / Q000494:pharmacology / Q000502:physiology*; D002352:Carrier Proteins; D004058:Diffusion; D004305:Dose-Response Relationship, Drug; D004625:Embryo, Nonmammalian / Q000196:embryology / Q000502:physiology; D008666:Metalloendopeptidases / Q000502:physiology; D011506:Proteins / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology; D016212:Transforming Growth Factor beta / Q000502:physiology; D014981:Xenopus / Q000196:embryology*; D029867:Xenopus Proteins; D029961:Zebrafish Proteins; D000099176:Noggin Protein
D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D002352:Carrier Proteins; D008666:Metalloendopeptidases; D011506:Proteins; D016212:Transforming Growth Factor beta; D029867:Xenopus Proteins; D029961:Zebrafish Proteins; D000099176:Noggin Protein; C525812:bmp4 protein, Xenopus; C525813:bmp4 protein, zebrafish; C109187:TLL2 protein, Xenopus