Aggregation of fibrillin molecules via disulphide bonds is postulated to be an early step in microfibril assembly. By expressing fragments of fibrillin 1 and fibrillin 2 in a mammalian expression system, we found that the N-terminal region of each protein directs the formation of homodimers and that disulphide bonds stabilize this interaction. A large fragment of fibrillin 1 containing much of the region downstream from the N-terminus remained as a monomer when expressed in the same cell system, indicating that this region of the protein lacks dimerization domains. This finding also confirms that the overexpression of fibrillin fragments does not in itself lead to spurious dimer formation. Pulse-chase analysis demonstrated that dimer formation occurred intracellularly, suggesting that the process of fibrillin aggregation is initiated early after biosynthesis of the molecules. These findings also implicate the N-terminal region of fibrillin 1 and fibrillin 2 in directing the formation of a dimer intermediate that aggregates to form the functional microfibril.
N-terminal domains of fibrillin 1 and fibrillin 2 direct the formation of homodimers: a possible first step in microfibril assembly
- Views Icon Views
- PDF LinkPDF
- Share Icon Share
- Cite Icon Cite
Timothy M. TRASK, Timothy M. RITTY, Thomas BROEKELMANN, Clarina TISDALE, Robert P. MECHAM; N-terminal domains of fibrillin 1 and fibrillin 2 direct the formation of homodimers: a possible first step in microfibril assembly. Biochem J 15 June 1999; 340 (3): 693–701. doi: https://doi.org/10.1042/bj3400693
Download citation file: