Decoding Ca2+ signals: a question of timing.
Receptor-stimulated Ca2+ signals come in several flavors. The Ca2+ signals can be decoded linearly or by integration of the response. How the duration of the signal conveyed by cytosolic Ca2+ concentration ([Ca2+]i) changes is regulated is not well understood. Liu et al. (Liu, Q., S.A. Walker, D. Gao, J.A. Taylor, Y.-F. Dai, R.S. Arkell, M.D. Bootman, H.L. Roderick, P.J. Cullen, and P.J. Lockyer. 2005. J. Cell Biol. 170:183-190) now report an example of decoding based on the differential regulation of Ras function by two Ca2+-sensitive Ras inhibitors: Ca2+-promoted Ras activator (CAPRI), which extends the duration of the effect of Ca2+ on Ras activity, and Ras GTPase activating-like protein (RASAL), which functions as a linear decoder of the Ca2+ signal.
Muallem
Shmuel
S
Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA. shmuel.muallem@utsouthwestern.edu
D000595:Amino Acid Sequence; D000818:Animals; D020013:Calcium Signaling / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D011905:Genes, ras; D006801:Humans; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D015290:Second Messenger Systems / Q000502:physiology; D020703:ras GTPase-Activating Proteins / Q000378:metabolism*; D018631:ras Proteins / Q000502:physiology*
C491144:RASA4 protein, human; D020703:ras GTPase-Activating Proteins; D018631:ras Proteins