Roles of phosphorylation of ERM proteins and ERM-binding membrane proteins in cellular morphogenesis

一曰：ERM-binding membrane proteins过度表达的影响（CD 43、CD 44和ICAM-2）对微绒毛形成的影响这些膜蛋白在L和CV 1细胞中的过表达导致微绒毛的延长，表明这些蛋白与ERM蛋白一起是微绒毛的主要成分。2：在COOH末端苏氨酸残基磷酸化的ERM蛋白（CPERMs）的定位我们开发了新的固定方案，使用三氯乙酸作为固定剂，以确定精确定位的CPERMs。3：ERM蛋白在细胞形态发生中的活化使用Rho抑制剂C3、蛋白激酶抑制剂staurosporine和PIP 2抑制剂新霉素揭示了Rho活性和ERM蛋白磷酸化的重要性取决于细胞类型。然而，发现PIP 2对于ERM蛋白的活化以及微绒毛的形成无一例外地是必需的。

1 : Effects of overexpression of ERM-binding membrane proteins (CD43, CD44 and ICAM-2) on microvilli formationOverexpression of these membrane proteins in L and CV1 cells resulted in elongation of microvilli, indicating these proteins are major components of microvilli together with ERM proteins.2 : Localization of ERM proteins phosphorylated at the COOH-terminal threonine residue (CPERMs)We developed new fixation protocol using trichloroacetic acid as a fixative to determine precise localization of CPERMs. They were localized just beneath the plasma membrane of microvilli, reflecting that CPERMs are activated ERM proteins as membrane-cytoskeleton cross-linkers.3 : ERM protein activation in cellular morphogenesisUse of Rho inhibitor, C3, protein kinase inhibitor, staurosporine, and PIP2 inhibitor, neomycin revealed that importance of Rho activity and phosphorylation of ERM proteins depends on cell type. However PIP2 was found to be essential without exception for activation of ERM proteins as well as microvilli formation.