Matrix Gla Protein Binds to Fibronectin and Enhances Cell Attachment and Spreading on Fibronectin
A study by S. K. Nishimoto and M. Nishimoto of the University of Tennessee Health Science Center, Matrix Gla Protein Binds to Fibronectin and Enhances Cell Attachment and Spreading on Fibronectin, has made several interesting observations. The study investigated a potential mechanism for MGP to bind to matrix proteins and alter cell matrix interactions. We outline some of their findings below.
Matrix Gla protein (MGP) is a member of a family of vitamin-K2 dependent, Gla-containing proteins. MGP is vital for inhibiting calcification in the extracellular matrix, particularly in cartilage and arteries.
Fibronectin is an extracellular matrix protein involved in cell adhesion, growth, migration, and differentiation. It has major roles in biological processes such as wound healing and embryonic development. Fibronectin is useful for the induction of cell attachment to a variety of surfaces including plastic and glass tissue culture labware, petri dishes, coverslips, microcarrier beads, etc.
- MGP Binds to Fibronectin and the First Type III Domain of Fibronectin.
- Fibronectin Binds a C-Terminal Peptide of MGP Comprised of Amino Acids 61 to 77.
- MGP Is Incorporated into Transglutaminase Crosslinked Fibronectin.
- MGP Becomes Crosslinked to Fibronectin III1-C.
- MGP Enhances Cell Attachment to Fibronectin.
- Cell Spreading on Fibronectin is Augmented by MGP.
- MGP Localizes in Embryonic Tissues in the Same Areas as Fibronectin.
MGP Enhances Cell Attachment and Spreading on Fibronectin
Cells attach and spread better on fibronectin and MGP coated surfaces than to fibronectin alone, even though MGP itself has no cell attachment activity.
Figure 1. MGP enhances cell attachment to fibronectin. MGP alone did not mediate cell attachment. The y-axis is HeLa cell binding indicated as absorbance at 595 nm. The x-axis is the log of fibronectin concentration from 0 to 3.3 μg/mL either with 3 μg/mL MGP (◯) or control buffer (●). MGP did not enhance cell attachment for 0 fibronectin (not shown, logarithmic plot).
Figure 2. MGP augments cell spreading on fibronectin. The graph shows the calculated cell area/cell for fibronectin coated surfaces compared to fibronectin plus MGP coated surfaces. FN is fibronectin alone open bars at 0.4 μg/mL (left) or 0.2 μg/mL (right); FN + MGP dark bars is the indicated concentration of fibronectin plus MGP at 3 μg/mL. The asterisk indicates that the combination of FN + MGP was significantly different from FN at each concentration of FN (P ≤ .0001, error bars are SEM). The average cell area from a minimum of 100 cells in 14 to 16 random microscopic fields is shown. Cells were allowed to attach for 2 hours in serum-free medium then fixed, stained, and imaged and the cell area quantified. Area per cell was determined by NIH Image software as described in experimental procedures.
To read more in depth on this topic, please visit the link to the published paper below:
Nishimoto, Satoru Ken, and Miyako Nishimoto. “Matrix gla protein binds to fibronectin and enhances cell attachment and spreading on fibronectin.” International journal of cell biology vol. 2014 (2014): 807013. doi:10.1155/2014/807013