User:Andy Maloney/Notebook/Lab Notebook of Andy Maloney/2009/05/08/Kinetic analysis of GTP hydrolysis associated with tubulin polymerization review

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Disclaimer

These are my thoughts on this paper. Read the paper before you read my comments please.

Paper

Kinetic analysis of GTP hydrolysis associated with tubulin polymerization

Review

So I started out with this question

Question: How does tubulin polymerize into microtubules?

This paper gives me at least a reference for what is already known in the field and that is, tubulin carries GTP on both its Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://api.formulasearchengine.com/v1/":): {\displaystyle \alpha} and Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://api.formulasearchengine.com/v1/":): {\displaystyle \beta} subunits. When two tubulin heterodimers combine, the Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://api.formulasearchengine.com/v1/":): {\displaystyle \beta} site hydrolyzes GTP to form GDP. I think the GDP gets stuck but I'm not sure.

  • They note that microtubules can be stabilized with nonhydrolyzable analogues of GTP such as GMPCPP.
  • I got another reference where they actually show GTP hydrolysis occurs at the Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://api.formulasearchengine.com/v1/":): {\displaystyle \beta} subunit, Reference.
  • They also state that free GTP in solution can be exchanged with bound GTP on tubulin that has been polymerized into microtubules.

Take home This was a nice paper that answered the question for me of "where are the references that say GTP is needed". Of course, I still don't understand why polymerization needs magnesium ions.