What is the difference between tight junctions and desmosomes?

[pm1]

Thank you! 🙂

---

Members don't see this ad.

 

[rjosh33]

I remember emailing my cell bio prof. this exact same question. This was her answer:

.Tight junctions and desmosomes have rather different structures. Tight junctions are made of a protein that is arranged within the membrane as a series of proteins that look more or less like beads. There are many of them lined up and then many lines that intersect. They cause the cells to be more or less sealed together. Desmosomes contain the protein cadherin. There are cadhereins on each cell and they come together at this point, but there are just more or less spots. Because they seal cells together, tight junctions have the role of preventing materials from going between cells, as I said. Desmosomes provide attachment points so cells are linked together. On the inside they are connected to intermediate filaments, which stretch across cells providing structural support. So, they are more related to integrating the support of the epithelium. If you look at Chapter 7 in the text, you can find more complete information..

.

Hope that helps.
.

 

[pm1]

thank you!

so I guess the take away points is that tight junctions if to prevent materials from going in between cells, while desmosomes if more of a attachment purpose.

that helps a lot! 🙂 thanks again!

 

[rjosh33]

thank you!

so I guess the take away points is that tight junctions if to prevent materials from going in between cells, while desmosomes if more of a attachment purpose.

that helps a lot! 🙂 thanks again!

Yep, you got it. Also, tight junctions have the important role of keeping transmembrane proteins isolated to their respective surface. Otherwise, an integral protein like a cell surface receptor could laterally diffuse along the membrane to the basolateral side, where it would be virtually useless. Because tight junctions wrap around the entire three dimensional cell, they prevent such diffusion.

 

[MedPR]

thank you!

so I guess the take away points is that tight junctions if to prevent materials from going in between cells, while desmosomes if more of a attachment purpose.

that helps a lot! 🙂 thanks again!

This is exactly what you need to know for the MCAT. Nothing more, nothing less.