Meet E Cadherin!

E Cadherin is a membrane protein that helps cells stick to other cells at cell junctions. Cell junctions are critical for forming and maintaining healthy tissues. Could you imagine if your skin cells suddenly couldn’t stick together?! E Cadherin is one of the proteins that makes sure our skin, and every other part of our body, remains intact!

On the left is a diagram of two cells next to each other. The cell membranes are labeled pink.

On the right is a zoomed-in diagram of the area where the two cells are touching. It shows two E Cadherin proteins, one embedded in each cell's membrane, sticking to each other.
E Cadherins on two cells are sticking the cells together.

E Cadherin has three main parts: one on the outside of the cell, one on the inside of the cell, and one in the cell membrane.

Three-dimensional molecular model of two E Cadherin proteins sticking together. These models only show the parts that stick out of the cell. Each E Cadherin has a structure like a string or a noodle, and they stick to each other at the very ends. Calcium ions are indicated and they bind in several places along the protein.

On the inside of the cell, E Cadherin’s mates, the catenins, help it interact with actin. Actin is a protein that makes up part of the cytoskeleton (you can read Actin about here), so it can solidly anchor E Cadherin in place. If something pulls on E Cadherin from the outside, it won’t just slip out of the membrane because it is holding on tightly to actin.

Diagram of E Cadherin being anchored to an actin filament on the inside of the cell. Several proteins are shown holding E Cadherin to actin.
E Cadherin is connected to actin on the inside of the cell by several proteins called catenins.

You can find E Cadherin’s adhesive area on the outside of the cell. This area sticks to E Cadherins (or similar Cadherin proteins) on other cells.

Also on the outside of the cell, calcium ions can bind to E Cadherin. Calcium ions provide E Cadherin with information about the environment so it can decide what kinds of partners to stick to, or to avoid sticking at all.

E Cadherin’s role in “cell stickiness,” and its ability to change its stickiness, make it a really important player in development and in cancer.

Development, a single cell becoming a whole organism is a complex process. It is important for each generation of cells to know where to go and what to do. E Cadherin (and an army of other proteins also) helps a cell know where it is, where other cells are, what kinds of cells are around it, and what kinds of cells it should stick to.

Cartoon of an eight-cell embryo. Cells are asking questions:

Where am I?

Is anyone there?

Which way is up?

What cell type are you?

Which of you should I stick to?
The cells in an early-stage embryo need to gather a lot of information as they develop.
(E Cadherin answers a lot of their questions.)

In regards to cancer, E Cadherin is sometimes called a “tumor suppresser.” This label implies that E Cadherin can prevent cancer, which isn’t exactly the case. But when E Cadherin fails to do its job, cancer can result. It is much easier for a tumor cell to exit the tissue, migrate, and wreak havoc elsewhere in the body when its E Cadherins are not making it stick to its neighboring cells.

A diagram of an unhealthy, un-sticky tumor cell (which has weak E Cadherins or no E Cadherins) leaving its place among the other cells.
An un-sticky tumor cell with weak E Cadherins is able to leave its position.

Thank your E Cadherins today for allowing your body to form correctly in your mother’s womb and for keeping all of your tissues (like your skin) intact!

Pećina-Slaus N. (2003). Tumor suppressor gene E-cadherin and its role in normal and malignant cells. Cancer cell international3(1), 17. https://doi.org/10.1186/1475-2867-3-17

Kim, S. A., Tai, C. Y., Mok, L. P., Mosser, E. A., & Schuman, E. M. (2011). Calcium-dependent dynamics of cadherin interactions at cell-cell junctions. Proceedings of the National Academy of Sciences of the United States of America108(24), 9857–9862. https://doi.org/10.1073/pnas.1019003108

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