Phenotypes of SERCA and PMCA knockout mice.

Area of Science:

• Biochemistry
• Molecular Biology
• Physiology

Background:

• P-type Ca2+-ATPases, including sarco(endo)plasmic reticulum Ca2+-ATPases (SERCAs) and plasma membrane Ca2+-ATPases (PMCAs), are crucial for maintaining cellular calcium gradients.
• These gradients are essential for regulating Ca2+-mediated signaling and various biological functions.

Purpose of the Study:

• To investigate the in vivo functions of SERCA and PMCA isoforms through gene-targeting studies.
• To elucidate the physiological roles and pathophysiological consequences of SERCA and PMCA dysfunction.

Main Methods:

• Gene-targeting studies were performed on various SERCA (isoforms 1, 2, 3) and PMCA (isoforms 1, 2, 4) deficient or heterozygous mutant mice.
• Phenotypic analysis was conducted to assess the impact of pump dysfunction on physiological processes.

Main Results:

• Studies confirmed known functions, such as SERCA1/2 in excitation-contraction coupling and PMCA1/SERCA2 in housekeeping.
• Unexpected phenotypes were observed: squamous cell cancer and altered exocytosis regulation in SERCA2 mutants, modulated Ca2+ signaling in SERCA3-deficient mice, deafness/balance issues in PMCA2 nulls, and male infertility in PMCA4 nulls.

Conclusions:

• Gene-targeting studies reveal diverse and critical roles for SERCAs and PMCAs in higher-order physiological processes.
• Dysfunction of these calcium pumps leads to significant pathophysiological consequences, underscoring their importance in health and disease.
• These findings provide novel insights into the cellular functions and clinical relevance of calcium ATPases.