A new article published in Matrix Biology reported that null mutations in CRTAP or P3H1—en¬-coding cartilage-associated protein and prolyl 3-hydroxylase 1—cause severe bone dysplasias – types VII and VIII osteogenesis imperfecta. The authors discussed that the lack of either protein prevents formation of the ER prolyl 3-hydroxylation complex – responsible for catalyzing 3Hyp modification of types I and II collagen and also acts as a collagen chaperone. This article clarified that 3-hydroxylation of the A1 site α1(I)P986 affects collagen crosslinking and structural organization. Whereas, its absence does not directly cause recessive bone dysplasia. In summary, it was stated that functions of the modification complex as a collagen chaperone are distinct from its role as prolyl 3-hydroxylase.

Source: Matrix Biology. 2020 Feb 26. pii: S0945-053X(20)30013-5. doi: 10.1016/j.matbio.2020.02.003.