Epithelial and ectomesenchymal role of the type I TGF-beta receptor ALK5 during facial morphogenesis and palatal fusion

Summary, in English

Transforming growth factor beta (TGF-beta) proteins play important roles in morphogenesis of many cramofacial tissues; however, detailed biological mechanisms of TGF-beta action, particularly in vivo, are still poorly understood. Here, we deleted the TGF-beta type I receptor gene Alk5 specifically in the embryonic ectodermal and neural crest cell lineages. Failure in signaling via this receptor, either in the epithelium or in the mesenchyme, caused severe craniofacial defects including cleft palate. Moreover, the facial phenotypes of neural crest-specific Alk5 mutants included devastating facial cleft and appeared significantly more severe than the defects seen in corresponding mutants lacking the TGF-beta type II receptor (TGF beta II), a prototypical binding partner of ALK5. Our data indicate that ALK5 plays unique, non-redundant cell-autonomous roles during facial development. Remarkable divergence between Tgfbr2 and A1k5 phenotypes, together with our biochemical in vitro data, imply that (1) ALK5 mediates signaling of a diverse set of ligands not limited to the three isoforms of TGF-beta, and (2) ALK5 acts also in conjunction with type II receptors other than TGF beta RII. (c) 2006 Elsevier Inc. All rights reserved.

• Author: Marek Dudas; Jieun Kim; Wai-Yee Li; Andre Nagy; Jonas Larsson; Stefan Karlsson; Yang Chai; Vesa Kaartinen
• Department/s: Division of Molecular Medicine and Gene Therapy
• Publishing year: 2006
• Language: English
• Pages: 298-314
• Publication/Series: Developmental Biology
• Volume: 296
• Issue: 2
• Links: http://dx.doi.org/10.1016/j.ydbio.2006.05.030
• Document type: Journal article
• Publisher: Elsevier
• Topic: Hematology
• Keywords: mandible; malformation; craniofacial; cranial neural crest; cleft palate; ALK5; cleft face; palatal fusion
• Status: Published
• ISBN/ISSN/Other: ISSN: 1095-564X