Characterization of a novel missense mutation in the prodomain of GDF5, which underlies brachydactyly type C and mild Grebe type chondrodysplasia in a large Pakistani family
- Authors:
- DOI:
- 10.1007/s00439-013-1330-3
- Abstract:
- All TGF-beta family members have a prodomain that is important for secretion. Lack of secretion of a TGF-beta family member GDF5 is known to underlie some skeletal abnormalities, such as brachydactyly type C that is characterized by a huge and unexplained phenotypic variability. To search for potential phenotypic modifiers regulating secretion of GDF5, we compared cells overexpressing wild type (Wt) GDF5 and GDF5 with a novel mutation in the prodomain identified in a large Pakistani family with Brachydactyly type C and mild Grebe type chondrodyslplasia (c527T>C; p.Leu176Pro). Initial in vitro expression studies revealed that the p.Leu176Pro mutant (Mut) GDF5 was not secreted outside the cells. We subsequently showed that GDF5 was capable of forming a complex with latent transforming growth factor binding proteins, LTBP1 and LTBP2. Furthermore, secretion of LTBP1 and LTBP2 was severely impaired in cells expressing the Mut-GDF5 compared to Wt-GDF5. Finally, we demonstrated that secretion of Wt-GDF5 was inhibited by the Mut-GDF5, but only when LTBP (LTBP1 or LTBP2) was co-expressed. Based on these findings, we suggest a novel model, where the dosage of secretory co-factors or stabilizing proteins like LTBP1 and LTBP2 in the microenvironment may affect the extent of GDF5 secretion and thereby function as modifiers in phenotypes caused by GDF5 mutations.
- Type:
- Journal article
- Language:
- English
- Published in:
- Human Genetics, 2013, Vol 132, Issue 11, p. 1253-1264
- Main Research Area:
- Medical science
- Publication Status:
- Published
- Review type:
- Peer Review
- Submission year:
- 2013
- Scientific Level:
- Scientific
- ID:
- 247018822
