Rodewald R, Newman S B, Karnovsky M J
J Cell Biol. 1976 Sep;70(3):541-54. doi: 10.1083/jcb.70.3.541.
Brush borders isolated from epithelial cells from the small intestine of neonatal rats are able to contract in the presence of ATP and Mg2+; Ca2+ is not required. Contraction is characterized by a pinching-in of the plasma membrane in the region of the zonula adherens and a subsequent rounding of the brush borders. No movement or consistent shortening of the microvilli is observed. The contraction appears to involve the 5- to 7-nm diameter microfilaments in the terminal web which associate with the zonula adherens. These filaments bind heavy meromyosin as do the actin core filaments of the microvilli. A model for contraction is presented in which, in the intact cell, terminal web filaments and core filaments interact to produce shortening of the microvilli.
从新生大鼠小肠上皮细胞分离出的刷状缘,在存在ATP和Mg2+的情况下能够收缩;不需要Ca2+。收缩的特征是黏着小带区域的质膜向内凹陷,随后刷状缘变圆。未观察到微绒毛有移动或持续缩短的情况。收缩似乎涉及终末网中直径为5至7纳米的微丝,这些微丝与黏着小带相关联。这些微丝与微绒毛的肌动蛋白核心丝一样能结合重酶解肌球蛋白。本文提出了一个收缩模型,即在完整细胞中,终末网丝和核心丝相互作用导致微绒毛缩短。