Bio

Honors & Awards


  • Dr. Bruce Brandhorst Graduate Prize, Simon Fraser University (2013)
  • Travel and Minor Research Award (TMRA), Simon Fraser University (2012-2013)
  • Wayerhaeuser Graduate Scholarship, Simon Fraser University (2012)
  • Graduate Research Fellowship,, Simon Fraser University (2011)
  • Graduate Research Fellowship, Simon Fraser University (2010)
  • President PhD research Stipend, Simon Fraser University (2010)
  • Poster Award, Loon Lake Cell Biology Retreat (April 2010)
  • Poster Award, Annual Departmental Graduate Colloquium (March 2010)
  • Junior Research Fellowship, National Center for Biological Sciences (2006-2007)

Boards, Advisory Committees, Professional Organizations


  • Treasurer, Vancouver Area Worm Research Meeting (VanWoRM) (2010 - 2011)
  • Organizing committee member, Vancouver Area Worm Research Meeting (VanWoRM) (2009 - 2010)
  • Organizing committee member, Biotechnology Workshops BIOEXPO 2001 and BIOEXPO 2002 (2001 - 2002)
  • Organizing committee member, Association Meeting REPLICA 2000 and REPLICA 2001 (2000 - 2001)

Professional Education


  • Master of Science, University Of Madras (2004)
  • Bachelor of Science, University Of Madras (2001)
  • Doctor of Philosophy, Simon Fraser University (2014)

Stanford Advisors


Publications

Journal Articles


  • Striated Rootlet and Nonfilamentous Forms of Rootletin Maintain Ciliary Function CURRENT BIOLOGY Mohan, S., Timbers, T. A., Kennedy, J., Blacque, O. E., Leroux, M. R. 2013; 23 (20): 2016-2022

    Abstract

    Primary cilia are microtubule-based sensory organelles whose structures and functions must be actively maintained throughout animal lifespan to support signal transduction pathways essential for development and physiological processes such as vision and olfaction [1]. Remarkably, few cellular components aside from the intraflagellar transport (IFT) machinery are implicated in ciliary maintenance [2]. Rootletin, an evolutionarily conserved protein found as prominent striated rootlets or a nonfilamentous form, both of which are associated with cilium-anchoring basal bodies, represents a likely candidate given its well-known role in preventing ciliary photoreceptor degeneration in a mouse model [3, 4]. Whether rootletin is universally required for maintaining ciliary integrity, and if so, by what mechanism, remains unresolved. Here, we demonstrate that the gene disrupted in the previously isolated C. elegans chemosensory mutant che-10 encodes a rootletin ortholog that localizes proximally and distally to basal bodies of cilia harboring or lacking conspicuous rootlets. In vivo analyses reveal that CHE-10/rootletin maintains ciliary integrity partly by modulating the assembly, motility, and flux of IFT particles, which are critical for axoneme length control. Surprisingly, CHE-10/rootletin is also essential for stabilizing ciliary transition zones and basal bodies, roles not ascribed to IFT. Unifying these findings, we provide evidence that the underlying molecular defects in the che-10 mutant stem from disrupted organization/function of the periciliary membrane, affecting the efficient delivery of basal body-associated and ciliary components and resulting in cilium degeneration. Together, our cloning and functional analyses of C. elegans che-10 provide the first mechanistic insights into how filamentous and nonfilamentous forms of rootletin play essential roles in maintaining ciliary function in metazoans.

    View details for DOI 10.1016/j.cub.2013.08.033

    View details for Web of Science ID 000326317300023

    View details for PubMedID 24094853

  • Transcriptional profiling of C. elegans DAF-19 uncovers a ciliary base-associated protein and a CDK/CCRK/LF2p-related kinase required for intraflagellar transport DEVELOPMENTAL BIOLOGY Phirke, P., Efimenko, E., Mohan, S., Burghoorn, J., Crona, F., Bakhoum, M. W., Trieb, M., Schuske, K., Jorgensen, E. M., Piasecki, B. P., Leroux, M. R., Swoboda, P. 2011; 357 (1): 235-247

    Abstract

    Cilia are ubiquitous cell surface projections that mediate various sensory- and motility-based processes and are implicated in a growing number of multi-organ genetic disorders termed ciliopathies. To identify new components required for cilium biogenesis and function, we sought to further define and validate the transcriptional targets of DAF-19, the ciliogenic C. elegans RFX transcription factor. Transcriptional profiling of daf-19 mutants (which do not form cilia) and wild-type animals was performed using embryos staged to when the cell types developing cilia in the worm, the ciliated sensory neurons (CSNs), still differentiate. Comparisons between the two populations revealed 881 differentially regulated genes with greater than a 1.5-fold increase or decrease in expression. A subset of these was confirmed by quantitative RT-PCR. Transgenic worms expressing transcriptional GFP fusions revealed CSN-specific expression patterns for 11 of 14 candidate genes. We show that two uncharacterized candidate genes, termed dyf-17 and dyf-18 because their corresponding mutants display dye-filling (Dyf) defects, are important for ciliogenesis. DYF-17 localizes at the base of cilia and is specifically required for building the distal segment of sensory cilia. DYF-18 is an evolutionarily conserved CDK7/CCRK/LF2p-related serine/threonine kinase that is necessary for the proper function of intraflagellar transport, a process critical for cilium biogenesis. Together, our microarray study identifies targets of the evolutionarily conserved RFX transcription factor, DAF-19, providing a rich dataset from which to uncover-in addition to DYF-17 and DYF-18-cellular components important for cilium formation and function.

    View details for DOI 10.1016/j.ydbio.2011.06.028

    View details for Web of Science ID 000294144800024

    View details for PubMedID 21740898

  • MKS and NPHP modules cooperate to establish basal body/transition zone membrane associations and ciliary gate function during ciliogenesis JOURNAL OF CELL BIOLOGY Williams, C. L., Li, C., Kida, K., Inglis, P. N., Mohan, S., Semenec, L., Bialas, N. J., Stupay, R. M., Chen, N., Blacque, O. E., Yoder, B. K., Leroux, M. R. 2011; 192 (6): 1023-1041

    Abstract

    Meckel-Gruber syndrome (MKS), nephronophthisis (NPHP), and related ciliopathies present with overlapping phenotypes and display considerable allelism between at least twelve different genes of largely unexplained function. We demonstrate that the conserved C. elegans B9 domain (MKS-1, MKSR-1, and MKSR-2), MKS-3/TMEM67, MKS-5/RPGRIP1L, MKS-6/CC2D2A, NPHP-1, and NPHP-4 proteins exhibit essential, collective functions at the transition zone (TZ), an underappreciated region at the base of all cilia characterized by Y-shaped assemblages that link axoneme microtubules to surrounding membrane. These TZ proteins functionally interact as members of two distinct modules, which together contribute to an early ciliogenic event. Specifically, MKS/MKSR/NPHP proteins establish basal body/TZ membrane attachments before or coinciding with intraflagellar transport-dependent axoneme extension and subsequently restrict accumulation of nonciliary components within the ciliary compartment. Together, our findings uncover a unified role for eight TZ-localized proteins in basal body anchoring and establishing a ciliary gate during ciliogenesis, and suggest that disrupting ciliary gate function contributes to phenotypic features of the MKS/NPHP disease spectrum.

    View details for DOI 10.1083/jcb.201012116

    View details for Web of Science ID 000288986200013

    View details for PubMedID 21422230

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