An effector molecule is

made by a pathogen to enhance the pathogen’s colonizing

abilities.

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#Unit 4. Cell Communication and Cell Signaling

The adhesiveness of cadherins depends on the presence of extracellular Ca2+

TLS Online TPP Program

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#Unit 4. Cell Communication and Cell Signaling

Two type of Cadherins:

1. Classical cadherin proteins

2. Nonclassical cadherin proteins

TLS Online TPP Program

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#Unit 4. Cell Communication and Cell Signaling

Extracellular region of a classical cadherin contains five copies of the cadherin domain separated by flexible hinge regions

TLS Online TPP Program

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#Unit 4. Cell Communication and Cell Signaling

Ca2+ ions bind to sites near each hinge and prevent it

from flexing, so that the whole string of cadherin domains behaves as a rigid and slightly curved rod to generate cell–cell adhesion

TLS Online TPP Program

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#Unit 4. Cell Communication and Cell Signaling

In absence of Ca2+, 

the hinges can flex, the structure becomes floppy & adhesion fails

TLS Online TPP Program

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#Unit 4. Cell Communication and Cell Signaling

Each classical cadherin molecule contains: 

A single TM domain

A short C-terminal cytosolic domain

Five extracellular “cadherin” domains (EC1–EC5)