Dataset Information

Cyclic nucleotide-gated channels on the flagellum control Ca2+ entry into sperm.

ABSTRACT: Cyclic nucleotide-gated (CNG) channels are key elements of cGMP- and cAMP-signaling pathways in vertebrate photoreceptor cells and in olfactory sensory neurons, respectively. These channels form heterooligomeric complexes composed of at least two distinct subunits (alpha and beta). The alpha subunit of cone photoreceptors is also present in mammalian sperm. Here we identify one short and several long less abundant transcripts of beta subunits in testis. The alpha and beta subunits are expressed in a characteristic temporal and spatial pattern in sperm and precursor cells. In mature sperm, the alpha subunit is observed along the entire flagellum, whereas the short beta subunit is restricted to the principal piece of the flagellum. These findings suggest that different forms of CNG channels coexist in the flagellum. Confocal microscopy in conjunction with the Ca2+ indicator Fluo-3 shows that the CNG channels serve as a Ca2+ entry pathway that responds more sensitively to cGMP than to cAMP. Assuming that CNG channel subtypes differ in their Ca2+ permeability, dissimilar localization of alpha and beta subunits may give rise to a pattern of Ca2+ microdomains along the flagellum, thereby providing the structural basis for control of flagellar bending waves.

SUBMITTER: Wiesner B

PROVIDER: S-EPMC2133051 | biostudies-literature | 1998 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Analysis of transcriptome in moss Physcomitrella patens CNGCb null mutant at 25 and 34 degrees C for 30 minutes. Results provide insight into role of CNGCb in acquired thermotolerance induced by non-lethal heat treatment. Typically at dawn of a hot summer day, land plants need precise molecular thermometers to sense harmless increments in the ambient temperature to timely develop a heat-shock response (HSR) and accumulate protective heat shock proteins (Hsps), in anticipation of upcoming harmful temperatures at mid-day. Here, we found that the CNGCb gene from Physcomitrella patens and its Arabidopsis ortholog CNGC2, encode for a component of cyclic nucleotide gated Ca2+ channels acting as the primary thermosensors of land plant cells. Disruption of CNGCb or CNGC2 produced a hyper-thermosensitive phenotype, giving rise to a HSR and acquired thermotolerance at significantly milder heat-priming treatments than in wild type plants. In an aequorin-expressing moss, CNGCb loss-of-function caused altered Ca2+ signaling and a sustained Ca2+ influx. Patch clamp recordings on moss protoplasts showed the presence of three distinct thermo-responsive Ca2+-channels in wild type cells. Deletion of CNGCb led to a total absence of one, and it increased the open probability of the remaining two thermo-responsive Ca2+ channels. Thus, both in Arabidopsis and moss, CNGC2 and CNGCb are expected to form with other related CNGCs, heteromeric Ca2+ channels in the plasma membrane that respond to mild increments in the ambient temperature by triggering an optimal HSR, leading to the onset of plant acquired thermotolerance. The WT moss tissues were heat-shocked for a half an hour at 34°C and 38°C and CNGCb at 25and 34°C followed by liquid nitrogen freezing. Total RNA was isolated using RNeasy Mini Kit (QIAGEN, Hilden, Germany) and two biological replicate samples for each treatment, were extracted. An Agilent-certified microarray service lab (MOgene, LC, St. Louis, MO, USA) was used to verify the integrity of the RNA and perform the microarray experiments. Two biological replicates were performed.

Dataset Information

Cyclic nucleotide-gated channels on the flagellum control Ca2+ entry into sperm.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets