FcεRI signalling through Lyn and Syk kinases also activates E3 ubiquitin ligases, including c-Cbl. Cbl ubiquitinylates Lyn and Syk, as well as FcεRI itself, triggering their degradation.

TLS Online TPP Program

#Id: 1527

#Unit 2. Cellular Organization

The short (∼20 amino acid) C-terminal tails of both α- and β-tubulin that protrude from the microtubule are enriched in glutamic and aspartic acids, the surface of the microtubule possesses a net negative charge.

TLS Online TPP Program

#Id: 1528

#Unit 2. Cellular Organization

Many MAPs are positively charged and bind to microtubles through electrostatic interactions.

TLS Online TPP Program

#Id: 1529

#Unit 2. Cellular Organization

MAPs are members of the tau family of proteins, which stabilize microtubules:

Tau 

MAP2

MAP4

TLS Online TPP Program

#Id: 1530

#Unit 2. Cellular Organization

MAPs (Tau, MAP2, MAP4 ) have two key domains:

1. Side-binding domains

2. Projection domains

TLS Online TPP Program

#Id: 1531

#Unit 2. Cellular Organization

When stabilizing MAPs coat the outer wall of a microtubule, they can increase the growth rate of microtubules or reduce catastrophe frequency.

TLS Online TPP Program

#Id: 1532

#Unit 2. Cellular Organization

The activity of the MAPs is regulated by the reversible phosphorylation of their projection domains.