Milting H, Heilmeyer L M, Thieleczek R
Institut für Physiologische Chemie, Ruhr-Universität, Bochum, Germany.
FEBS Lett. 1994 May 30;345(2-3):211-8. doi: 10.1016/0014-5793(94)00440-4.
The total membrane concentrations of PtdIns, PtdIns4P, and PtdIns(4,5)P2 contribute to the functional capacity of the Ins(1,4,5)P3 signalling system which is operating in skeletal muscle but the function of which is still unknown. Total amounts of these phosphoinositides have been determined in purified membranes of transverse tubules (TT) and terminal cisternae (TC) of the sarcoplasmic reticulum (SR) of rabbit skeletal muscle. PtdIns and PtdIns4P have been detected in both membrane systems whereas PtdIns(4,5)P2 (290 mumol/mol phospholipid) is confined only to TT. A much greater pool of PtdIns(4,5)P2 seems, however, to be located in the sarcolemma away from the triadic junction.
磷脂酰肌醇（PtdIns）、磷脂酰肌醇-4-磷酸（PtdIns4P）和磷脂酰肌醇-4,5-二磷酸（PtdIns(4,5)P2）的总膜浓度对存在于骨骼肌中、功能仍不明的肌醇-1,4,5-三磷酸（Ins(1,4,5)P3）信号系统的功能能力有影响。已测定了兔骨骼肌肌浆网（SR）横管（TT）和终池（TC）纯化膜中这些磷酸肌醇的总量。在这两种膜系统中均检测到了PtdIns和PtdIns4P，而PtdIns(4,5)P2（290 μmol/mol磷脂）仅局限于横管。然而，似乎有更大的PtdIns(4,5)P2池位于远离三联体连接的肌膜中。
