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Updated: Jul 13, 2026
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Dissection of Local Ca2+ Signals in Cultured Cells by Membrane-targeted Ca2+ Indicators
Published on: March 22, 2019
Homer proteins in Ca2+ signaling by excitable and non-excitable cells
Paul F Worley1, Weizhong Zeng, Guojin Huang
1The Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. pworley@jhmi.edu
Cell Calcium
|July 10, 2007
Summary
Homers are crucial calcium (Ca2+) signaling regulators, not just passive scaffolds. They fine-tune protein activity and ion channel function, ensuring precise calcium signal transmission.
Area of Science:
- Cellular Biology
- Molecular Signaling
- Biochemistry
Background:
- Homers are scaffolding proteins involved in organizing calcium (Ca2+) signaling complexes.
- Their role extends beyond passive scaffolding to active regulation of signaling components.
Purpose of the Study:
- To elucidate the isoform-specific regulatory functions of Homer proteins in calcium signaling.
- To understand how Homer proteins modulate the activity of various ion channels and signaling molecules.
Main Methods:
- The study likely involved molecular biology techniques, protein interaction assays, and electrophysiology to assess protein function and calcium signaling dynamics.
- Specific methods may include Western blotting, co-immunoprecipitation, calcium imaging, and patch-clamp electrophysiology.
Main Results:
- Homer2 enhances GTPase-activating protein (GAP) activity of RGS proteins and PLCbeta, accelerating Galpha subunit activity.
- Homer1 regulates TRPC channel activity, membrane trafficking, and coupling with IP3Rs.
- Homer1 stimulates L-type Ca2+ channels (Ca(v)1.2 and Ca(v)1.3) and mediates communication between RyR2 and Ca(v)1.2 for excitation-contraction coupling.
- Homers act as buffers, reducing Ca2+ signal intensity and ensuring spatial-temporal fidelity.
Conclusions:
- Homers are dynamic regulators, not passive scaffolds, with isoform-specific roles in calcium signaling.
- Their buffering capacity is essential for maintaining signal fidelity and precise downstream activation.
- Understanding Homer function is key to comprehending cellular calcium dynamics and related physiological processes.
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