Concentration, compartmentation and metabolic function of intracellular free Mg2+.
Intracellular total Mg2+ and free Mg2+ are compartmentalized between cell organelles and within the cytosol. Different values of [Mg2+]i in the cytosol of the same cell type were measured by various investigators. A main reason for the differences is the uncertainty of the dissociation constants used for the Mg furaptra complex in the fluorescence method and for MgATP when 31P NMR was employed. The more realistic KD values of Mg furaptra and MgATP measured under in situ conditions are higher than the KDs used by most investigators. The [Mg2+]is obtained and the KDs used by various authors were presented. The role of intracellular Mg2, in metabolic functions and the action of various effectors on [Mg2+]i and [Ca2+] was reviewed. Intracellular Mg2+ may have a permissive role supporting the effector-induced mechanisms that are mediated by Ca2+ as a second messenger.
Günther
T
T
Charité-Universitätsmedizin Berlin, Campus Benjamin Franklin, Institutfür Molekularbiologie und Biochemie, Arnimallee 22, 14195 Berlin, Germany.
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002451:Cell Compartmentation; D003600:Cytosol / Q000378:metabolism; D016257:Fura-2 / Q000031:analogs & derivatives; D006801:Humans; D007700:Kinetics; D008274:Magnesium / Q000032:analysis / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008839:Microelectrodes; D009369:Neoplasms / Q000378:metabolism; D015388:Organelles / Q000378:metabolism; D015290:Second Messenger Systems
C058776:2-(2-(5-carboxy)oxazole)-5-hydroxy-6-aminobenzofuran-N,N,O-triacetic acid; D000255:Adenosine Triphosphate; D008274:Magnesium; D002118:Calcium; D016257:Fura-2