Ca2+ waves, Ca2+ oscillations, local Ca2+spikes and puffs – intracellular Ca2+ signalling is very complex. Well, it gets worse: Annunziata De Luisi and Aldebaran Hofer now reveal that extracellular Ca2+ levels oscillate too (see p. 1527). They show that stimulation of the extracellular Ca2+ receptor CaR (a G-protein-coupled receptor that monitors extracellular Ca2+)produces oscillations in intracellular Ca2+ levels in clusters of adjacent HEK293 cells. Since the oscillations are unaffected by gap junction inhibitors, the authors speculated that they might be transmitted by release of Ca2+ through plasma membrane Ca2+ pumps (PMCAs) and its activation of CaRs on neighbouring cells. Indeed, De Luisi and Hofer demonstrate that PMCA inhibitors (e.g. HgCl2) block the response,as do buffers that maintain extracellular Ca2+ at a constant level(e.g. BAPTA free acid). They also use the near-membrane Ca2+ probe fura-C18 to show that activation of CaRs produces local oscillations in the extracellular Ca2+ concentration. Since the CaRs and PMCAs appear to reside in specific membrane microdomains, the authors suggest that local extracellular Ca2+ oscillations in these regions help to reinforce the intracellular oscillations.
Calcium oscillates in and out!
Calcium oscillates in and out!. J Cell Sci 15 April 2003; 116 (8): e802. doi:
Download citation file:
Advertisement
Cited by
Call for papers - Cilia and Flagella: from Basic Biology to Disease
We are welcoming submissions for our upcoming special issue: Cilia and Flagella: from Basic Biology to Disease. This issue will be coordinated by two Guest Editors: Pleasantine Mill (University of Edinburgh) and Lotte Pedersen (University of Copenhagen). Submission deadline: 1 March 2025.
Biologists @ 100 - join us in Liverpool in March 2025
We are excited to invite you to a unique scientific conference, celebrating the 100-year anniversary of The Company of Biologists, and bringing together our different communities. The conference will incorporate the Spring Meetings of the BSCB and the BSDB, the JEB Symposium Sensory Perception in a Changing World and a DMM programme on antimicrobial resistance. Find out more and register your interest to join us in March 2025 in Liverpool, UK.
Principles and regulation of mechanosensing
Mechanics play a fundamental role in cell physiology and represent physical mechanisms which cells use to influence function from the molecular to tissue scale. In this Review, Stefano Sala and colleagues clearly define mechanosensing and mechanotransduction, illustrate various mechanosensing mechanisms and discuss methods that cells use to regulate these processes.
JCS-FocalPlane Training Grants
Early-career researchers - working in an area covered by JCS - who would like to attend a microscopy training course, please apply. Deadline dates for 2024 applications: 7 September (decision by week commencing 8 October 2024); 22 November (decision by week commencing 16 December).
HIV-1 assembly – when virology meets biophysics
Claire Lacouture and colleagues review mechanisms of assembly of the HIV-1 structural protein Gag from biophysical and biological perspectives. The researchers highlight how HIV-1 Gag hijacks host cell factors associated with cortical actin machinery to make new viral particles.