R35GM140631

The biology of motile cilia - Cilia are microtubule-based cellular extensions that play key roles in sensing the extracellular environment, processing developmental signals, and generating propulsive force and fluid flow. They also act as secretory organelles, releasing bioactive vesicular ectosomes involved in cell-cell communication and other processes. Cilia are ancient and complex; in humans, approximately 5% of all genes are involved in their formation/activity, and defects result in complex syndromes or ciliopathies.

For many years, my laboratory has been broadly interested in the assembly and function of motile cilia and has a strong record of identifying new opportunities and pursuing them to reveal novel aspects of ciliary biology. Most recently, we demonstrated that cilia act as a source of peptidergic signals. For most studies, we utilize the biciliate unicellular green alga Chlamydomonas as a model due to the ease of biochemical analysis and large array of molecular genetic approaches available.

Over the next five years, we will pursue two broad areas of focus to address what I consider key questions in ciliary biology. Although superficially distinct, these two areas are intimately connected, and I anticipate we will be able to integrate them to yield novel insights into conserved and essential cilia-based pathways.

1) Ciliary Motility: Dissecting the dynein motors and control systems that generate ciliary beating and power retrograde intraflagellar transport (IFT). We plan to focus on three major issues. We will dissect the complex pathways by which axonemal and IFT dyneins are synthesized and assembled in the cytoplasm, employing our newly devised biochemical fractionation methods. Building a cilium is an immensely complex problem in macromolecular assembly, and we will examine how assembly factors control the axonemal incorporation of outer dynein arms at precise locations on doublet microtubules. We will also study axonemal dynein motor regulation to a) determine how responses to alterations in Ca2+ and redox poise are combined with curvature sensing to yield integrated changes in motility, and b) assess how cells sense imposed changes in ciliary beating and respond by increasing intraciliary levels of the dynein regulator LIS1.

2) Cilia Formation and Peptidergic Signaling: Studying the peptide amidating enzyme (peptidylglycine-amidating monooxygenase; PAM) and its amidated bioactive products in ciliary assembly and cilia-based cell-cell communication. We recently demonstrated that active PAM occurs in cilia and that PAM loss leads to the failure of ciliogenesis and disrupts dynein-driven retrograde IFT. Furthermore, PAM-generated amidated bioactive products are released in cilia-derived vesicular ectosomes, and one acts as a chemotactic modulator. We will build on these observations to identify novel amidated PAM products involved in cilia formation. We will dissect the pathways leading to regulated amidated product release in ciliary ectosomes and determine where/when processing of the precursors occurs. We will also pursue the amidated product receptors and their downstream signaling pathways, which lead to differential regulation of the two motile cilia and chemotaxis.

University Of Connecticut Health Center

THE NATIONAL INSTITUTE OF GENERAL MEDICAL SCIENCES (NIGMS) SUPPORTS BASIC RESEARCH THAT INCREASES OUR UNDERSTANDING OF BIOLOGICAL PROCESSES AND LAYS THE FOUNDATION FOR ADVANCES IN DISEASE DIAGNOSIS, TREATMENT, AND PREVENTION. NIGMS ALSO SUPPORTS RESEARCH IN SPECIFIC CLINICAL AREAS THAT AFFECT MULTIPLE ORGAN SYSTEMS: ANESTHESIOLOGY AND PERI-OPERATIVE PAIN, CLINICAL PHARMACOLOGY ?COMMON TO MULTIPLE DRUGS AND TREATMENTS, AND INJURY, CRITICAL ILLNESS, SEPSIS, AND WOUND HEALING.? NIGMS-FUNDED SCIENTISTS INVESTIGATE HOW LIVING SYSTEMS WORK AT A RANGE OF LEVELSFROM MOLECULES AND CELLS TO TISSUES AND ORGANSIN RESEARCH ORGANISMS, HUMANS, AND POPULATIONS. ADDITIONALLY, TO ENSURE THE VITALITY AND CONTINUED PRODUCTIVITY OF THE RESEARCH ENTERPRISE, NIGMS PROVIDES LEADERSHIP IN SUPPORTING THE TRAINING OF THE NEXT GENERATION OF SCIENTISTS, ENHANCING THE DIVERSITY OF THE SCIENTIFIC WORKFORCE, AND DEVELOPING RESEARCH CAPACITY THROUGHOUT THE COUNTRY.

93.859 - Biomedical Research and Research Training

National Institute of General Medical Sciences (NIGMS) [HHS - NIH]

Farmington, Connecticut 06030 United States

Single Zip Code

Maximizing Investigators' Research Award (R35 - Clinical Trial Optional) (PAR-19-367)

Amendment Since initial award the total obligations have increased 699% from $428,978 to $3,428,570.