title: Simultaneous rather than ordered cleavage of two sites within the BMP4 prodomain leads to loss of ligand in mice.
abstract: ProBMP4 is generated as a latent precursor that is sequentially cleaved at two sites within the prodomain to generate an active ligand. An initial cleavage occurs adjacent to the ligand domain, which generates a non-covalently associated prodomain/ligand complex that is subsequently dissociated by cleavage at an upstream site. An outstanding question is whether the two sites need to be cleaved sequentially and in the correct order to achieve proper control of BMP4 signaling during development. In the current studies, we demonstrate that mice carrying a knock-in point mutation that causes simultaneous rather than sequential cleavage of both prodomain sites show loss of BMP4 function and die during mid-embryogenesis. Levels of mature BMP4 are severely reduced in mutants, although levels of precursor and cleaved prodomain are unchanged compared with wild type. Our biochemical analysis supports a model in which the transient prodomain/ligand complex that forms during sequential cleavage plays an essential role in prodomain-mediated stabilization of the mature ligand until it can acquire protection from degradation by other means. By contrast, simultaneous cleavage causes premature release of the ligand from the prodomain, leading to destabilization of the ligand and loss of signaling in vivo.
authors.affiliation: Department of Cell and Developmental Biology, Oregon Health and Sciences University, School of Medicine, Portland, OR 97239-3098, USA.
authors.forename: Anup
authors.initials: A
authors.lastname: Tilak
authors.affiliation: Department of Cell and Developmental Biology, Oregon Health and Sciences University, School of Medicine, Portland, OR 97239-3098, USA.
authors.forename: Sylvia M
authors.initials: SM
authors.lastname: Nelsen
authors.affiliation: Department of Neurobiology and Anatomy and Internal Medicine, Division of Hematology and Hematologic Malignancies, University of Utah, School of Medicine, Salt Lake City, UT 94132, USA.
authors.forename: Hyung-Seok
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Department of Cell and Developmental Biology, Oregon Health and Sciences University, School of Medicine, Portland, OR 97239-3098, USA.
authors.forename: Nathan
authors.initials: N
authors.lastname: Donley
authors.affiliation: Department of Neurobiology and Anatomy and Internal Medicine, Division of Hematology and Hematologic Malignancies, University of Utah, School of Medicine, Salt Lake City, UT 94132, USA.
authors.forename: Autumn
authors.initials: A
authors.lastname: McKnite
authors.affiliation: Department of Cell and Developmental Biology, Oregon Health and Sciences University, School of Medicine, Portland, OR 97239-3098, USA.
authors.forename: Hyunjung
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Neurobiology and Anatomy and Internal Medicine, Division of Hematology and Hematologic Malignancies, University of Utah, School of Medicine, Salt Lake City, UT 94132, USA jan.christian@neuro.utah.edu.
authors.forename: Jan L
authors.initials: JL
authors.lastname: Christian
mesh_terms: D000483:Alleles; D020816:Amino Acid Motifs; D000818:Animals; D001665:Binding Sites; D019521:Body Patterning; D055415:Bone Morphogenetic Protein 4 / Q000737:chemistry*; D003433:Crosses, Genetic; D057809:HEK293 Cells; D006801:Humans; D008024:Ligands; D051379:Mice; D009154:Mutation; D010641:Phenotype; D011485:Protein Binding; D015398:Signal Transduction; D029867:Xenopus Proteins / Q000737:chemistry*; D014982:Xenopus laevis
chemical_list: C525809:BMP4 protein, human; C525810:Bmp4 protein, mouse; D055415:Bone Morphogenetic Protein 4; D008024:Ligands; D029867:Xenopus Proteins; C525812:bmp4 protein, Xenopus
keywords: Bone morphogenetic protein 4; Prodomain; Proprotein convertase