The remarkable sensitivity and specificity of odorant detection in the mammalian olfactory system derives from highly specialized cellular and molecular components. GPCRs present in the cilia of the olfactory neurons activate a transduction cascade leading to electrical activity and the propagation of sensory information to the brain. The discovery of a large family of olfactory receptor (OR) genes provided an explanation for the differential sensitivity of individual olfactory neurons. Functional expression of ORs in heterologous systems represent an opportunity to define the molecular basis of odorant recognition and has led to modest progress in directing the efficient trafficking of these proteins. However, we know very little about the mechanisms utilized by native sensory neurons to create the highly specialized sensory cilia and localize critical components, including transduction proteins and odorant receptors to these structures. We recently demonstrated that individuals with genetic defects in components of the intraflagellar transport (IFT) system display profound olfactory deficits that are recapitulated in murine models of this disease. These observations provide a foundation for examining the general process of transport in an in vivo system and understanding how specialized integral membrane proteins are moved to specific locations within the cell. We propose to define the molecular apparatus used in sensory neurons to direct the trafficking of signal transduction components. The evolution and structural conservation of olfactory receptors make them uniquely amenable to a systematic dissection of molecular sorting and subcellular localization. We will utilize molecular and functional approaches to visualize and elucidate the dynamics of cilia formation, OR distribution and transduction protein localization. These experiments will complement those derived from in vitro analysis by providing information on receptor trafficking in a native context. These experiments afford new insights into the development of olfactory sensory neurons, pathways for the translocation of tissue-specific proteins to sensory organelles and the establishment of neuronal connectivity. The trafficking of proteins to specific cellular locations and the development of specialized cilia is critical to many cell types in mammals. Our studies should provide valuable new information regarding the pathogenesis of human diseases of sensory perception and cilia-dependent cellular function.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC004553-10
Application #
8011304
Study Section
Somatosensory and Chemosensory Systems Study Section (SCS)
Program Officer
Sullivan, Susan L
Project Start
2000-07-01
Project End
2012-12-31
Budget Start
2011-01-01
Budget End
2012-12-31
Support Year
10
Fiscal Year
2011
Total Cost
$400,444
Indirect Cost
Name
Johns Hopkins University
Department
Biochemistry
Type
Schools of Medicine
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Paix, Alexandre; Folkmann, Andrew; Goldman, Daniel H et al. (2017) Precision genome editing using synthesis-dependent repair of Cas9-induced DNA breaks. Proc Natl Acad Sci U S A 114:E10745-E10754
Sharma, Tanu; Reed, Randall R (2013) Balancing survival: the role of CTGF in controlling experience-modulated olfactory circuitry. Neuron 79:1037-9
Bermingham-McDonogh, Olivia; Corwin, Jeffrey T; Hauswirth, William W et al. (2012) Regenerative medicine for the special senses: restoring the inputs. J Neurosci 32:14053-7
McIntyre, Jeremy C; Davis, Erica E; Joiner, Ariell et al. (2012) Gene therapy rescues cilia defects and restores olfactory function in a mammalian ciliopathy model. Nat Med 18:1423-8
Roby, Yang A; Bushey, Michael A; Cheng, Li E et al. (2012) Zfp423/OAZ mutation reveals the importance of Olf/EBF transcription activity in olfactory neuronal maturation. J Neurosci 32:13679-88a
Bennett, Mosi K; Kulaga, Heather M; Reed, Randall R (2010) Odor-evoked gene regulation and visualization in olfactory receptor neurons. Mol Cell Neurosci 43:353-62
Yu, Huimin; Smallwood, Philip M; Wang, Yanshu et al. (2010) Frizzled 1 and frizzled 2 genes function in palate, ventricular septum and neural tube closure: general implications for tissue fusion processes. Development 137:3707-17
Leinders-Zufall, Trese; Cockerham, Renee E; Michalakis, Stylianos et al. (2007) Contribution of the receptor guanylyl cyclase GC-D to chemosensory function in the olfactory epithelium. Proc Natl Acad Sci U S A 104:14507-12
Grubb, Barbara R; Rogers, Troy D; Kulaga, Heather M et al. (2007) Olfactory epithelia exhibit progressive functional and morphological defects in CF mice. Am J Physiol Cell Physiol 293:C574-83