Interaction of calmodulin with L-selectin at the membrane interface: implication on the regulation of L-selectin shedding.
Interaction of calmodulin with L-selectin at the membrane interface: implication on the regulation of L-selectin shedding.
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DOI：
10.1016/j.jmb.2011.05.041
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发表时间：
2011-08-05
影响因子：
5.6
通讯作者：
Li R
中科院分区：
文献类型：
--
作者：
Deng W;Srinivasan S;Zheng X;Putkey JA;Li R
胞外域脱落的钙调素假说规定，钙调素，细胞内Ca 2+依赖性调节蛋白，与L-选择素的胞质结构域相关联，以调节L-选择素在质膜另一侧的胞外域脱落。为了了解潜在的分子机制，我们已经表征了钙调素与来自人L-选择素的两种肽的相互作用。肽ARR 18对应于L-选择素的整个胞质结构域（成熟蛋白中的残基Ala 317-Tyr 334），CLS对应于残基Lys 280-Tyr 334，其含有L-选择素的整个跨膜和胞质结构域。通过荧光光谱和其他生物物理技术监测相互作用，我们发现钙调素可以与水溶液中的ARR 18或磷脂酰胆碱双层中重构的CLS的L-选择素胞质结构域结合，两者的亲和力均为约2 μM。该协会是钙独立的，动态的，涉及两个叶的钙调蛋白。在磷脂双层中，CLS的带正电荷的L-选择素胞质结构域通过静电相互作用与膜界面处的阴离子磷脂酰丝氨酸脂质相关联。在磷脂酰丝氨酸含量模拟细胞质膜内小叶的磷脂酰丝氨酸含量的条件下，钙调蛋白和CLS之间的相互作用变得不可检测。这些结果表明，钙调素与L-选择素在细胞中的协会可以通过膜双层的影响，和阴离子脂质可以调节跨膜受体的胞外域脱落。
The calmodulin hypothesis of ectodomain shedding stipulates that calmodulin, an intracellular Ca2+-dependent regulatory protein, associates with the cytoplasmic domain of L-selectin to regulate ectodomain shedding of L-selectin on the other side of the plasma membrane. To understand the underlying molecular mechanism, we have characterized the interactions of calmodulin with two peptides derived from human L-selectin. The peptide ARR18 corresponds to the entire cytoplasmic domain of L-selectin (residues Ala317–Tyr334 in the mature protein), and CLS corresponds to residues Lys280–Tyr334, which contains the entire transmembrane and cytoplasmic domains of L-selectin. Monitoring the interaction by fluorescence spectroscopy and other biophysical techniques, we found that calmodulin can bind to ARR18 in aqueous solutions or the L-selectin cytoplasmic domain of CLS reconstituted in the phosphatidylcholine bilayer, both with an affinity of approximate 2 μM. The association is calcium-independent, dynamic and involves both lobes of calmodulin. In a phospholipid bilayer, the positively charged L-selectin cytoplasmic domain of CLS is associated with anionic phosphatidylserine lipids at the membrane interface through electrostatic interactions. Under conditions where the phosphatidylserine content mimics that in the inner leaflet of the cell plasma membrane, the interaction between calmodulin and CLS becomes undetectable. These results suggest that the association of calmodulin with L-selectin in the cell can be influenced by the membrane bilayer, and that anionic lipids may modulate ectodomain shedding of transmembrane receptors.
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DOI：
10.1074/jbc.m806983200
发表时间：
2009-03-27
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Killock DJ;Parsons M;Zarrouk M;Ameer-Beg SM;Ridley AJ;Haskard DO;Zvelebil M;Ivetic A
通讯作者：
Ivetic A
DOI：
10.1084/jem.182.2.519
发表时间：
1995-08-01
期刊：
The Journal of experimental medicine
影响因子：
--
作者：
Chen A;Engel P;Tedder TF
通讯作者：
Tedder TF
影响因子：
2.9
作者：
LEHRER, SS
通讯作者：
LEHRER, SS
影响因子：
4.1
作者：
Díaz-Rodríguez, E;Esparís-Ogando, A;Pandiella, A
通讯作者：
Pandiella, A
影响因子：
56.9
作者：
MEADOR, WE;MEANS, AR;QUIOCHO, FA
通讯作者：
QUIOCHO, FA