- B.S., 1993, Shandong University, China, Microbiology.
- Ph.D., 1999, The Institute of Microbiology, Chinese Academy of Sciences.
- Postdoctoral Research, Yale University, Department of Molecular, Cellular and Developmental Biology.
Joined the department in 2006
Qin Lab Website
College Station, TX 77843-3258
Biological Sciences Building West
Biological Sciences Building West
|Ciliogenesis and Intraflagellar Transport in Chlamydomonas and C. elegans
I am interested in ciliogenesis and intraflagellar transport (IFT). Cilia/flagella, including primary cilia and sensory cilia, are highly conserved organelles that project from the surface of many cells. Cilia play important roles in the cell biology and physiology of an organism. Dysfunctional cilia can lead to several human diseases, including polycystic kidney disease (PKD), retinitis pigmentosa and Bardet-Biedl syndrome (BBS). The assembly and maintenance of flagella is dependent on a motility process occurring underneath the flagellar membrane called intraflagellar transport (IFT). IFT is a microtubule dependent transport system, which moves non-membrane-bound particles from the cell body out to the tip of the cilium/flagellum, and then returns them to the cell body. We study this process by using model organisms of biflagellate green alga Chlamydomonas reinhardtii and small round worm Caenorhabditis elegans. Chlamydomonas is an excellent model system for the biochemical and molecular –genetic analysis of proteins and processes that occur in flagellum. C. elegans, on the other hand, is a model system that is amenable to easy mutational analysis of genes and has sixty sensory neurons that have various morphologically distinct types of sensory cilia at the distal end of their dendrites. Currently, the lab is focused on:
1) Characterizing IFT particle proteins
IFT particles are protein complexes composed of at least 17 different peptides. Although IFT is thought to be a transportation system, the role of each IFT particle component has not been studied extensively. It is quite possible that some of them are involved in cargo specificity and some of them are involved in integrating signals from other processes. To explore these possibilities, we cloned several new IFT genes from Chlamydomonas and will characterize each of them in detail.
2) Understanding how IFT is regulated.
IFT is a precisely regulated process. IFT particle must load and unload its cargo and change its motor at two turning points, the flagellar base and tip. So far it is little known about how IFT is regulated. We will use cell biological, biochemical and genetic approaches to identify proteins that play a role in regulating IFT.
3) Understanding how IFT is involved in ciliary sensory function.
The membranes of all eukaryotic motile (9 +2) and immotile primary (9 +0) cilia harbor channels and receptors involved in sensory transduction. These receptors are transported from the cytoplasm onto the ciliary membrane by targeted exocytosis of vesicles to a point adjacent to the ciliary basal body. We demonstrated that select GFP-tagged sensory receptors, once in the ciliary membrane, undergo rapid vectorial transport along the entire length of the cilia of Caenorhabditis elegans sensory neurons. This motility is disrupted in certain IFT mutants. Our current focus on this project is to further characterize this membrane protein movement and understand its role in ciliary sensory function.
- Qin H. Regulation of intraflagellar transport and ciliogenesis by small g proteins. Int Rev Cell Mol Biol. 2012;293:149-68.
- Behal RH, Miller MS, Qin H, Lucker B, Jones A, Cole DG. Subunit Interactions and Organization of the Chlamydomonas reinhardtii Intraflagellar Transport Complex A. J Biol Chem. 2011 Dec 14. [Epub ahead of print]
- Silva DA, Huang X, Behal RH, Cole DG, Qin H. The RABL5 homolog IFT22 regulates the cellular pool size and the amount of IFT particles partitioned to the flagellar compartment in Chlamydomonas reinhardtii. Cytoskeleton. 2011 Nov 10. doi: 10.1002/cm.20546. [Epub ahead of print]
- Williamson SM, Silva DA, Richey E, Qin H. Probing the role of IFT particle complex A and B in flagellar entry and exit of IFT-dynein in Chlamydomonas. Protoplasma. 2011 Aug 19. [Epub ahead of print]
- Fan ZC, Behal RH, Geimer S, Wang Z, Williamson SM, Zhang H, Cole DG, Qin H. Chlamydomonas IFT70/CrDYF-1 Is a Core Component of IFT Particle Complex B and Is Required for Flagellar Assembly. Mol Biol Cell. 2010 Jun 9. [Epub ahead of print]
- Wang Z, Fan Z-C, Williamson SM, Qin H, 2009 Intraflagellar Transport (IFT) Protein IFT25 Is a Phosphoprotein Component of IFT Complex B and Physically Interacts with IFT27 in Chlamydomonas. PLoS ONE 4(5): e5384. doi:10.1371/journal.pone.0005384
- Mukhopadhyay S, Lu Y, Qin H, Lanjuin A, Shaham S, Sengupta P. (2007) Distinct IFT mechanisms contribute to the generation of ciliary structural diversity in C. elegans. EMBO J. 26(12):2966-2980.
- Hou Y, Qin H, Follit JA, Pazour GJ, Rosenbaum JL, and Witman GB. (2007) IFT46, a Novel Intraflagellar Transport (IFT)-Particle Protein, Functions in Outer Dynein Arm Transport. J Cell Biol 176: 653-665.
- Qin H*, Wang Z*, Diener D, and Rosenbaum J. (2007) Intraflagellar Transport Protein 27 Is a Small G Protein Involved in Cell-Cycle Control. Curr Biol. (17) 193-202. * equal contribution
- Bae, Y, Qin H, Knobel K, Hu J, Rosenbaum JL, Bar MM. (2006) General and cell-type specific mechanisms target TRPP2/PKD-2 to cilia. Development. 133(19):3859-3870