Calcium signaling in B cells: regulation of cytosolic Ca2+ increase and its sensor molecules, STIM1 and STIM2.
Calcium signals are crucial for diverse cellular functions including adhesion, differentiation, proliferation, effector functions and gene expression. After engagement of the B cell receptor, the intracellular calcium ion (Ca(2+)) concentration is increased promoting the activation of various signaling cascades. While elevated Ca(2+) in the cytosol initially comes from the endoplasmic reticulum (ER), a continuous influx of extracellular Ca(2+) is required to maintain the increased level of cytosolic Ca(2+). Store-operated Ca(2+) entry manages this process, which is regulated by an ER calcium sensor, stromal interaction molecule (STIM). STIM proteins sense changes in the levels of Ca(2+) stored within the ER lumen and regulates the Ca(2+)-release activated Ca(2+) channel in the plasma membrane. This review focuses on the signaling pathways leading to Ca(2+) influx and the role of Ca(2+) signals in B cell functions.
Laboratory for Lymphocyte Differentiation, WPI Immunology Frontier Research Center, Osaka University, 3-1 Yamada-oka, Osaka 565-0871, Japan; Laboratory for Lymphocyte Differentiation, RIKEN Research Center for Integrative Medical Sciences (IMS-RCAI), 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.
Yoshihiro
Y
Baba
Laboratory for Lymphocyte Differentiation, WPI Immunology Frontier Research Center, Osaka University, 3-1 Yamada-oka, Osaka 565-0871, Japan; Laboratory for Lymphocyte Differentiation, RIKEN Research Center for Integrative Medical Sciences (IMS-RCAI), 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.
Masanori
M
Matsumoto
Laboratory for Lymphocyte Differentiation, WPI Immunology Frontier Research Center, Osaka University, 3-1 Yamada-oka, Osaka 565-0871, Japan; Laboratory for Lymphocyte Differentiation, RIKEN Research Center for Integrative Medical Sciences (IMS-RCAI), 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan. Electronic address: kurosaki@ifrec.osaka-u.ac.jp.
Tomohiro
T
Kurosaki
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D002118:Calcium / Q000276:immunology*; D020013:Calcium Signaling / Q000276:immunology*; D003600:Cytosol / Q000276:immunology*; D006801:Humans; D008565:Membrane Proteins / Q000276:immunology*; D011947:Receptors, Antigen, B-Cell / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology
D008565:Membrane Proteins; D011947:Receptors, Antigen, B-Cell; D002118:Calcium
Ca(2+) signal; IL-10; Store-operated Ca(2+) entry (SOCE); Stromal interaction molecule 1 (STIM1); regulatory B cell