Microtubules


Tubulin Posttranslational modifications

For many years we know that there are multiple tubulin genes available in eukaryotes and their gene products undergo extensive posttranslational modifications (PTMs). The microtubule cytoskeleton field has benefited immensely from tubulin purified from brain sources, however this often lead to oversimplification or ignorance towards the function of tubulin PTMs in cells. During my postdoctoral work at UCSF, we developed a robust system to purify tubulin with a unique PTM or isotype. When tested against kinesin and dynein motors each tubuin modification is sensed by a particular motor for its optimal function (Sirajuddin et al 2014). Currently in our lab we are extending this study in cellular systems to study the effects of tubulin PTMs in intracellular cargo transport. We are also interesting in understanding the function of tubuin PTMs in microtubule growth and dynamics.

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Microtubule minus end view with C-terminal tails (CTTs) modeled in red. The CTTs are the hotspot for tubulin PTMs and can send transmit cues to regulate motors and microtubule associated proteins.

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Non-canonical tubulins

α- and β-tubulin are the most popular and abundant tubulin in cells, apart from them there are other tubulin genes (non-canonical tubulin) widely present in eukaryote genome. Our goal is to study the structure and function of δ-, ε-, ζ-, η-, θ-tubulin genes.

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Phylogenetic tree of tubulin genes from human and Chlamydomonas reinhardtii.