Does depolymerisation take place at the minus end of microtubule?
Wikipedia says that
Dynamic instability refers to the coexistence of assembly and disassembly at the 'ends' of a microtubule.
but Karp's Cell Biology, 7th edition says
Dynamic instability is an inherent property of microtubule itself, more specifically, of the plus end of the microtubule.
I was of the opinion that the GTP bound to the minus end does not hydrolyse and so no depolymerisation take place at the minus end.
But again from The Cell: A Molecular Approach. 2nd edition I found that
treadmilling is a dynamic behavior in which tubulin molecules bound to GDP are continually lost from the minus end and replaced by the addition of tubulin molecules bound to GTP to the plus end of the same microtubule.
The concept I have developed so far is completely shattered by this treadmilling thing. Can you explain,
i) Whether GTP remains attached to the minus end?
ii) Whether depolymerisation occurs at the minus end?
iii) If depolymerisation does not occur, then is treadmilling a special condition?