title: Expression of adenylyl cyclase type I in cochlear inner hair cells.
abstract: Expression of calcium/calmodulin-activated adenylyl cyclase type I (ACI) mRNA has been determined in the cochlea and in an organ-of-Corti subdissected tissue fraction by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Amplification products of predicted size were obtained from the mouse cochlea and rat organ of Corti with nucleotide sequences corresponding to respective ACI brain transcripts. In addition, ACI template was detected in a rat inner hair cell cDNA library by PCR. Immunoreactivity to ACI has been localized within the organ of Corti to the inner hair cell, with diaminobenzidine staining found in both the cell body and in the stereocilia. Evidence, thus, has been obtained that both ACI transcript and protein are expressed in the inner hair cell, the primary mechanosensory receptor cell of the cochlea. We hypothesize that ACI is activated by calcium influx through a calcium/calmodulin interaction and that this adenytyl cyclase isoform may have a role in modulation of receptoneural afferent transmission and/or mechanosensory transduction in the cochlea.
authors.affiliation: Department of Otolaryngology, Wayne State University, Detroit, MI 48201, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Drescher
authors.forename: K M
authors.initials: KM
authors.lastname: Khan
authors.forename: K W
authors.initials: KW
authors.lastname: Beisel
authors.forename: A A
authors.initials: AA
authors.lastname: Karadaghy
authors.forename: J S
authors.initials: JS
authors.lastname: Hatfield
authors.forename: S Y
authors.initials: SY
authors.lastname: Kim
authors.forename: A J
authors.initials: AJ
authors.lastname: Drescher
authors.forename: J M
authors.initials: JM
authors.lastname: Lasak
authors.forename: R L
authors.initials: RL
authors.lastname: Barretto
authors.forename: A H
authors.initials: AH
authors.lastname: Shakir
authors.forename: D G
authors.initials: DG
authors.lastname: Drescher
mesh_terms: D000262:Adenylyl Cyclases / Q000096:biosynthesis*; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D018076:DNA, Complementary; D015723:Gene Library; D006199:Hair Cells, Auditory, Inner / Q000201:enzymology*; D051379:Mice; D008808:Mice, Inbred CBA; D008969:Molecular Sequence Data; D009925:Organ of Corti / Q000201:enzymology; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D011912:Rats, Inbred ACI; D014158:Transcription, Genetic
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D012333:RNA, Messenger; D000262:Adenylyl Cyclases; C106670:adenylyl cyclase 1