Jawdat Al-Bassam

Research Interests

Microtubules are dynamic tubular polymers that generate force inside cells, driving processes like cell division, development, and cell movement. They're built from alpha/beta (αβ)-tubulin dimers that assemble head-to-tail into protofilaments, which bundle side by side to form hollow tubes called microtubules. Kinesin motor proteins move along microtubules to transport cargo or organize mitotic spindles. Eukaryotic cells maintain high concentrations of αβ-tubulins, which assemble at microtubule ends and trigger GTP hydrolysis upon incorporation. Occasionally, assembly abruptly reverses in events called catastrophes, where the tube structure peels and rapidly falls apart. Newly made α- and β-tubulin proteins must be paired using GTP hydrolysis into αβ-tubulin, a process called tubulin biogenesis.

The Al-Bassam lab studies the structural mechanisms of microtubule-regulating machines: multi-subunit tubulin cofactor assemblies, which catalyze αβ-tubulin biogenesis from α- and β-tubulin using GTP hydrolysis; microtubule polymerases with multiple TOG (tumor overexpressed gene) domains, which add αβ-tubulin at microtubule ends; and microtubule depolymerases, which remove it using ATP hydrolysis. These machines exist across all eukaryotes, acting as tubulin "biogenesis factories" and as "polymerases" or "depolymerases" that drive tubulin buildup, addition, and removal at microtubule ends. The lab also studies mechanisms for the autoinhibition and activation of kinesin motors. Diverse mechanisms mediate this autoinhibition, until motors are activated to drive transport or organize microtubules into bipolar spindles during cell division.

The broader goal of the Al-Bassam lab is to understand the structural organization of these machines by capturing snapshots that reveal their transitions along with tubulin. We combine biochemistry with cryo-electron microscopy (cryo-EM), X-ray crystallography, and single-molecule fluorescence microscopy to connect molecular structure to function. Together, these approaches span scales from micrometers down to fractions of a nanometer, letting us link atomic structures to functional changes within protein domains.

Graduate Program Affiliations 

• Biochemistry, Molecular, Cellular and Developmental Biology Graduate Group
• Biophysics Graduate Group