Despite my two-year old daughter’s observation that gummy fruit snacks are great adhesive tools, the tissues in our body require something a bit more sophisticated to stick together. Different types of tissue need different specialized adhesion structures. For example, desmosomes function in heart and skin tissue, which are under a lot of mechanical stress. Today’s image is from a paper describing how some desmosome proteins get to the adhesion site.
Desmosomes are highly-ordered structures at the plasma membrane that adhere cells to one another, and play a crucial role in maintaining tissue integrity both during and after development. The adhesion properties of desmosomes are due to the presence of two different cadherin proteins, called Dsg and Dsc. A recent paper describes how these two cadherins are trafficked to desmosome adhesion sites. According to Nekrasova and colleagues, Dsg and Dsc are transported to desmosomes by two different kinesins, which are motors that walk along microtubules. Dsg is transported by kinesin-1, while Dsc is transported by kinesin-2. That each desmosome cadherin has its own transport pathway suggests that the assembly and function of desmosomes, and in turn adhesion, can be tailored throughout development and tissue remodeling. In the sequence of images above, Dsg (red, arrow) is migrating along microtubules (blue) towards the cell periphery.
Nekrasova, O., Amargo, E., Smith, W., Chen, J., Kreitzer, G., & Green, K. (2011). Desmosomal cadherins utilize distinct kinesins for assembly into desmosomes originally published in The Journal of Cell Biology, 195 (7), 1185-1203 DOI: 10.1083/jcb.201106057