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Multifaceted roles of STIM proteins
Robert Hooper1, Elsie Samakai, Joseph Kedra
1Department of Biochemistry, Temple University School of Medicine, 3440 North Broad Street, Philadelphia, PA, 19140, USA.
Pflugers Archiv : European Journal of Physiology
|April 10, 2013
Summary
Stromal interaction molecules (STIM1 and STIM2) sense calcium levels in the endoplasmic reticulum. These proteins also act as stress sensors, responding to oxidative stress, temperature, and hypoxia, influencing broader cellular functions beyond calcium entry.
Area of Science:
- Cellular Biology
- Molecular Biology
- Physiology
Background:
- Stromal interaction molecules (STIM1 and STIM2) are key regulators of store-operated calcium entry.
- STIM proteins sense calcium (Ca2+) depletion in the endoplasmic reticulum (ER).
- Upon sensing Ca2+ depletion, STIM proteins interact with Orai channels, facilitating Ca2+ influx into the cytosol.
Purpose of the Study:
- To explore the expanding roles of STIM proteins beyond their canonical function in calcium signaling.
- To discuss the implications of STIM proteins acting as sensors for various cellular stressors.
- To highlight the diverse range of STIM protein interactions and their impact on cellular physiology.
Main Methods:
- Literature review and synthesis of existing research on STIM proteins.
- Analysis of studies investigating STIM protein responses to different cellular conditions.
- Discussion of emerging evidence on STIM protein partnerships and functions.
Main Results:
- STIM proteins are increasingly recognized for sensing cellular stressors beyond ER Ca2+ levels, including oxidative stress, temperature changes, and hypoxia.
- The interaction partners of STIM proteins extend beyond the Orai channel family.
- STIM proteins modulate a wider array of physiological processes than previously understood.
Conclusions:
- STIM proteins possess broader sensory capabilities than initially thought, responding to diverse cellular stresses.
- The functional repertoire of STIM proteins is expanding, involving interactions with numerous partners.
- STIM proteins play a significant role as general modulators of cellular physiology, particularly under stress conditions.
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