The evolution of organellar calcium mapping technologies.

Area of Science:

• Cell Biology
• Physiology
• Biochemistry

Background:

• Intracellular calcium (Ca2+) dynamics are crucial for cellular functions, involving multiple organellar stores.
• Endolysosomes are increasingly recognized as key regulators of cellular Ca2+ but remain poorly understood.
• Traditional methods for mapping Ca2+ face challenges in the acidic endolysosomal environment.

Purpose of the Study:

• To review organellar Ca2+ pools and current knowledge.
• To discuss the limitations of traditional Ca2+ probes in acidic organelles.
• To highlight new Ca2+ probes for endolysosomal Ca2+ signaling.

Main Methods:

• Review of existing literature on organellar Ca2+ pools.
• Analysis of traditional chemical fluorescent probes and electrophysiological strategies.
• Discussion of novel Ca2+ probes and their sensing mechanisms.

Main Results:

• Traditional Ca2+ probes are limited by the acidic pH of endolysosomes.
• A new generation of Ca2+ probes offers improved capabilities for studying endolysosomal Ca2+.
• These novel probes provide critical insights into endolysosomal Ca2+ fluxes and their interactions with other organellar Ca2+ pools.

Conclusions:

• Endolysosomal Ca2+ plays a vital physiological role.
• Advanced Ca2+ probes are essential for overcoming limitations in studying endolysosomal Ca2+ signaling.
• Understanding endolysosomal Ca2+ dynamics is key to deciphering complex cellular Ca2+ signaling networks.