Descending part of the thin segment is highly permeable to water and moderately permeable to most Solutes (urea and sodium)

TLS Online TPP Program

#Id: 1542

#Unit 2. Cellular Organization

Op18/stathmin (End-Binding Proteins) binds selectively to curved protofilaments and enhances terminal tubulin heterodimer dissociation from a microtubule end. 

 

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