| Title: | Ultrastructural localization of G-proteins and the channel protein TRP2 to microvilli of rat vomeronasal receptor cells |
| Author(s): | Menco BP; Carr VM; Ezeh PI; Liman ER; Yankova MP; |
| Address: | "Department of Neurobiology and Physiology, Northwestern University, Evanston, Illinois 60208-3520, USA. bmenco@northwestern.edu" |
| ISSN/ISBN: | 0021-9967 (Print) 0021-9967 (Linking) |
| Abstract: | "Microvilli of vomeronasal organ (VNO) sensory epithelium receptor cells project into the VNO lumen. This lumen is continuous with the outside environment. Therefore, the microvilli are believed to be the subcellular sites of VNO receptor cells that interact with incoming VNO-targeted odors, including pheromones. Candidate molecules, which are implicated in VNO signaling cascades, are shown to be present in VNO receptor cells. However, ultrastructural evidence that such molecules are localized within the microvilli is sparse. The present study provides firm evidence that immunoreactivity for several candidate VNO signaling molecules, notably the G-protein subunits G(ialpha2) and G(oalpha), and the transient receptor potential channel 2 (TRP2), is localized prominently and selectively in VNO receptor cell microvilli. Although G(ialpha2) and G(oalpha) are localized separately in the microvilli of two cell types that are otherwise indistinguishable in their apical and microvillar morphology, the microvilli of both cell types are TRP2(+). VNO topographical distinctions were also apparent. Centrally within the VNO sensory epithelium, the numbers of receptor cells with G(ialpha2)(+) and G(oalpha)(+) microvilli were equal. However, near the sensory/non-sensory border, cells with G(ialpha2)(+) microvilli predominated. Scattered ciliated cells in this transition zone resembled neither VNO nor main olfactory organ (MO) receptor cells and may represent the same ciliated cells as those found in the non-sensory part of the VNO. Thus, this study shows that, analogous to the cilia of MO receptor cells, microvilli of VNO receptor cells are enriched selectively in proteins involved putatively in signal transduction. This provides important support for the role of these molecules in VNO signaling" |
| Keywords: | "Animals Calcium Channels/*metabolism Cell Compartmentation/physiology Cell Membrane/metabolism/ultrastructure GTP-Binding Proteins/*metabolism Immunohistochemistry Male Membrane Potentials/physiology Membrane Proteins/*metabolism Microscopy, Electron Micr;" |
| Notes: | "MedlineMenco, B P Carr, V M Ezeh, P I Liman, E R Yankova, M P eng DC02491/DC/NIDCD NIH HHS/ DC02774/DC/NIDCD NIH HHS/ DC04564/DC/NIDCD NIH HHS/ Research Support, U.S. Gov't, Non-P.H.S. Research Support, U.S. Gov't, P.H.S. 2001/09/18 J Comp Neurol. 2001 Oct 1; 438(4):468-89. doi: 10.1002/cne.1329" |
