Direct modulation of calmodulin targets by the neuronal calcium sensor NCS-1.

Abstract

Ca2+ and its ubiquitous intracellular receptor calmodulin (CaM)

GCY-8, PDE-2, and NCS-1 are critical elements of the cGMP-dependent thermotransduction cascade in the AFD neurons responsible for C. elegans thermotaxis

“…7, A and B). Frequenin, the human homologue of the C. elegans NCS-1 protein (Shaye and Greenwald, 2011), potentiates PDE activity in a calcium-dependent manner in vitro (Schaad et al, 1996). Thus, if C. elegans NCS-1 functions like its human counterpart, it is no surprise that loss of NCS-1 and PDE-2 produces similar effects on T *, holding current, and ThRC amplitude.…”

“…In vertebrate photoreceptors, GCAPs provide calciumdependent negative feedback to regulate cGMP synthesis (Schaad et al, 1996;Mendez et al, 2001). Given that ncs-1 is expressed in the AFD neurons and regulates behavioral responses to thermal gradients (Gomez et al, 2001), we hypothesized that NCS-1 protein might also help to fine-tune ThRCs.…”

The Diversity of Calcium Sensor Proteins in the Regulation of Neuronal Function

“…3) and in some cases these interactions overlap with those of calmodulin (Schaad et al 1996). This overlap using in vitro binding assays may not be physiologically meaningful because of substantial lower affinity of NCS-1 for known calmodulin targets (Schaad et al 1996;Fitzgerald et al 2008). NCS-1 has a higher affinity for calcium than calmodulin and therefore may preferentially interact with certain binding partners when the amplitude of a Ca 2þ -signal falls below the threshold for activation of calmodulin.…”

“…3) and in some cases these interactions overlap with those of calmodulin (Schaad et al 1996). This overlap using in vitro binding assays may not be physiologically meaningful because of substantial lower affinity of NCS-1 for known calmodulin targets (Schaad et al 1996;Fitzgerald et al 2008).…”

Genetic Analysis of Plant Salt Tolerance Using Arabidopsis

“…Functionally characterized proteins that are most similar to the SOS3 gene product are the B-subunit of calcineurin (Mendoza et al, 1994) and animal neuronal Ca sensors (NCS) (Schaad et al, 1996). Calcineurin is a Ca 2ϩ -and calmodulindependent protein phosphatase consisting of a catalytic A-subunit (CnA) and a regulatory B-subunit (CnB), which has four high affinity EF-hand Cabinding sites (Klee et al, 1988).…”