|
- 积分
- 17983
- 威望
- 17983
- 包包
- 26159
|
 * H7 V: p" I) i% M3 a) {
Volume 154, Issue 2
) w) B N) ^0 Y% pOn the cover: In this issue of Cell, Terasaki et al. (pp. 285–296)
1 k9 ~1 L6 t" x3 A texplain how parallel sheets of endoplasmic reticulum are connected. The
h# y1 B+ r% \# d; b: _7 S$ mexistence of these sheet stacks and their function in synthesis of membrane and + u! N: M( B. T2 B$ Q1 o9 i) u0 Q! q
secreted proteins has been known for more than 60 years. Three-dimensional & \! g0 \7 Y" {9 X- L" U4 ?: [
reconstructions from serial section electron micrographs from mouse salivary ' @ E& W0 ]9 j. v5 C( j9 v
gland show that the sheets are connected by twisted membrane surfaces with ' I4 y' M9 D0 D: e K1 j2 M
helical edges. The overall structure resembles a parking garage, in which the $ Z1 a7 c4 v" T4 a
different levels are connected by helicoidal ramps. Theoretical calculations
1 v9 [/ X2 V: F3 p: I; X) \7 }show that this structure minimizes the elastic energy of sheet edges and 2 l% Y3 D0 o4 S V5 m, }
surfaces and allows dense packing of this organelle in the restricted space of a 3 A- D6 n( T4 a; @2 l% l
cell.
5 X- w3 o, Y1 F9 k |
-
总评分: 威望 + 20
包包 + 20
查看全部评分
|
发表于 2013-7-19 19:50
发表于 2013-7-19 20:06
