Gα/GSA-1 works upstream of PKA/KIN-1 to regulate calcium signaling and contractility in the Caenorhabditis elegans spermatheca

English version

Autoři: Perla G. Castaneda ^aff001; Alyssa D. Cecchetelli ^aff001; Hannah N. Pettit ^aff001; Erin J. Cram ^aff001
Působiště autorů: Department of Biology, Northeastern University, Boston, MA, United States ^aff001
Vyšlo v časopise: Gα/GSA-1 works upstream of PKA/KIN-1 to regulate calcium signaling and contractility in the Caenorhabditis elegans spermatheca. PLoS Genet 16(8): e32767. doi:10.1371/journal.pgen.1008644
Kategorie: Research Article
doi: https://doi.org/10.1371/journal.pgen.1008644

Souhrn

Correct regulation of cell contractility is critical for the function of many biological systems. The reproductive system of the hermaphroditic nematode C. elegans contains a contractile tube of myoepithelial cells known as the spermatheca, which stores sperm and is the site of oocyte fertilization. Regulated contraction of the spermatheca pushes the embryo into the uterus. Cell contractility in the spermatheca is dependent on actin and myosin and is regulated, in part, by Ca²⁺ signaling through the phospholipase PLC-1, which mediates Ca²⁺ release from the endoplasmic reticulum. Here, we describe a novel role for GSA-1/Gα_s, and protein kinase A, composed of the catalytic subunit KIN-1/PKA-C and the regulatory subunit KIN-2/PKA-R, in the regulation of Ca²⁺ release and contractility in the C. elegans spermatheca. Without GSA-1/Gα_s or KIN-1/PKA-C, Ca²⁺ is not released, and oocytes become trapped in the spermatheca. Conversely, when PKA is activated through either a gain of function allele in GSA-1 (GSA-1(GF)) or by depletion of KIN-2/PKA-R, the transit times and total numbers, although not frequencies, of Ca²⁺ pulses are increased, and Ca²⁺ propagates across the spermatheca even in the absence of oocyte entry. In the spermathecal-uterine valve, loss of GSA-1/Gα_s or KIN-1/PKA-C results in sustained, high levels of Ca²⁺ and a loss of coordination between the spermathecal bag and sp-ut valve. Additionally, we show that depleting phosphodiesterase PDE-6 levels alters contractility and Ca²⁺ dynamics in the spermatheca, and that the GPB-1 and GPB-2 G_β subunits play a central role in regulating spermathecal contractility and Ca²⁺ signaling. This work identifies a signaling network in which Ca²⁺ and cAMP pathways work together to coordinate spermathecal contractions for successful ovulations.

Klíčová slova:

Caenorhabditis elegans – Embryos – Gonads – Muscle contraction – Oocytes – Ovulation – RNA interference – Uterus

Zdroje

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