TY - JOUR
T1 - Localization and expression of clarin-1, the Clrn1 gene product, in auditory hair cells and photoreceptors
AU - Zallocchi, Marisa
AU - Meehan, Daniel T.
AU - Delimont, Duane
AU - Askew, Charles
AU - Garige, Suneetha
AU - Gratton, Michael Anne
AU - Rothermund-Franklin, Christie A.
AU - Cosgrove, Dominic
N1 - Funding Information:
Supported by R01 DC004844 (to D.C.) and R01 DC 006442 (to M.A.G.). The authors gratefully acknowledge Skip Kennedy for expert preparation of figures, Mathew Holley and Dr. Marilyn Farquhar for the kind gift of UB/OC-1 cells and the mannosidase II antibodies, respectively. Confocal microscopy was conducted at the Integrative Biological Imaging Facility at Creighton University, Omaha, NE. This facility was constructed with support from C06 Grant RR17417-01 from the NCRR, NIH.
PY - 2009/9
Y1 - 2009/9
N2 - The Usher syndrome 3A (CLRN1) gene encodes clarin-1, which is a member of the tetraspanin family of transmembrane proteins. Although identified more than 6 years ago, little is known about its localization or function in the eye and ear. We developed a polyclonal antibody that react with all clarin-1 isoforms and used it to characterize protein expression in cochlea and retina. In the cochlea, we observe clarin-1expression in the stereocilia of P0 mice, and in synaptic terminals present at the base of the auditory hair cells from E18 to P6. In the retina, clarin-1 localizes to the connecting cilia, inner segment of photoreceptors and to the ribbon synapses. RT-PCR from P0 cochlea and P28 retina show mRNAs encoding only isoforms 2 and 3. Western blots show that only isoform 2 is present in protein extracts from these same tissues. We examined clarin-1 expression in the immortomouse-derived hair cell line UB/OC-1. Only isoform 2 is expressed in UB/OC-1 at both mRNA and protein levels, suggesting this isoform is biologically relevant to hair cell function. The protein co-localizes with microtubules and post-transgolgi vesicles. The subcellular localization of clarin-1 in hair cells and photoreceptors suggests it functions at both the basal and apical poles of neurosensoriepithelia.
AB - The Usher syndrome 3A (CLRN1) gene encodes clarin-1, which is a member of the tetraspanin family of transmembrane proteins. Although identified more than 6 years ago, little is known about its localization or function in the eye and ear. We developed a polyclonal antibody that react with all clarin-1 isoforms and used it to characterize protein expression in cochlea and retina. In the cochlea, we observe clarin-1expression in the stereocilia of P0 mice, and in synaptic terminals present at the base of the auditory hair cells from E18 to P6. In the retina, clarin-1 localizes to the connecting cilia, inner segment of photoreceptors and to the ribbon synapses. RT-PCR from P0 cochlea and P28 retina show mRNAs encoding only isoforms 2 and 3. Western blots show that only isoform 2 is present in protein extracts from these same tissues. We examined clarin-1 expression in the immortomouse-derived hair cell line UB/OC-1. Only isoform 2 is expressed in UB/OC-1 at both mRNA and protein levels, suggesting this isoform is biologically relevant to hair cell function. The protein co-localizes with microtubules and post-transgolgi vesicles. The subcellular localization of clarin-1 in hair cells and photoreceptors suggests it functions at both the basal and apical poles of neurosensoriepithelia.
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U2 - 10.1016/j.heares.2009.06.006
DO - 10.1016/j.heares.2009.06.006
M3 - Article
C2 - 19539019
AN - SCOPUS:67849128527
VL - 255
SP - 109
EP - 120
JO - Hearing Research
JF - Hearing Research
SN - 0378-5955
IS - 1-2
ER -