The goal of my lab is to understand the mechanisms that regulate cell and organelle growth. Most of our work is focused on the growth and disassembly of microtubules in eukaryotic cilia and flagella because these organelles can be approached with a variety of morphological, biochemical, and molecular biological techniques. Cilia and flagella are important organelles and function in reproduction (sperm), vision (vertebrate photoreceptors), sensory input (mechano and olfactory receptors), clearance of reproductive and respiratory tracts, and movements of many protozoans.
Flagella assemble and disassemble by the addition and removal of proteins at their distal ends. For assembly, proteins must be packaged, transported along the 5-10+ µm long flagellum, and then added to or along the ends of the microtubules. We are studying the functions of microtubule capping structures that link the ends of the microtubules to the flagellar membrane at the sites of flagellar assembly. The caps are the best known structures that link microtubule ends to membranes and appear to be involved in microtubule targeting and the regulation of microtubule assembly.
We use two approaches to study cap function. A biochemical approach involves isolating the caps and characterizing their interactions with microtubules in vitro. As important cap proteins are identified, their genes are identified and used to carry out molecular knock-out experiments to determine their function in vivo.
Our genetic approach is to isolate cap and flagellar assembly mutants in Chlamydomonas reinhardtii using insertional mutagenesis. Genes disrupted by insertional mutagenesis are being identified and characterized, as are the protein products of these genes. These mutants should reveal a variety of regulatory proteins, including proteins associated with the capping structures and proteins involved in signal transduction that regulate cap function.
Email Page
Print Page