A brief pulse of red light will induce a response, provided that the light is sufficiently bright, and conversely, very dim light will work if the irradiation time is long enough. 

This reciprocal relationship between fluence rate and time is known as the law of reciprocity

TLS Online TPP Program

#Id: 1543

#Unit 2. Cellular Organization

Stathmin decreases the effective concentration of tubulin subunits that are available for polymerization (an action analogous to the drug colchicine) and enhances that a growing microtubule will switch to the shrinking state.

TLS Online TPP Program

#Id: 1544

#Unit 2. Cellular Organization

Phosphorylation of stathmin inhibits its binding to tubulin.

TLS Online TPP Program

#Id: 1545

#Unit 2. Cellular Organization

Katanin promotes breakage by extracting tubulin subunits from the wall of the microtubule (also releases microtubules from MTOCs). 

 

TLS Online TPP Program

#Id: 1546

#Unit 2. Cellular Organization

Plectin links microtubules to intermediate filaments.

 

TLS Online TPP Program

#Id: 1547

#Unit 2. Cellular Organization

Taxol, 

A plant alkaloid from the Pacific yew tree

Binds microtubules and stabilizes them against depolymerization

TLS Online TPP Program

#Id: 1548

#Unit 2. Cellular Organization

Nocodazole and colchicine