核孔有沒有膜？ 有的話是幾層膜？

Question

核膜是雙層膜　四層磷脂質那核孔是如何的狀態？多謝了

Answer 1

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There is one good reference about nuclear pore from Scripps Institute in San Diego:

<http://www.scripps.edu/~stoffler/proj/NPC/npc.html... You can see the illustration and figures there as well.

The Nuclear Pore Complex

Molecular trafficking between the nucleus and the cytoplasm of interphase cells occurs via the nuclear pore complexes (NPCs), large supramolecular assemblies that are embedded in the double-membraned nuclear envelope (NE). The NPCs provide peripheral channels of about 9 nm in diameter, which allow the diffusion of ions and small molecules, and mediate the selective transport of nuclear proteins, RNAs, and ribonucleoprotein (RNP) particles by energy-dependent mechanisms.

The structure of the NPC has been extensively investigated by electron microscopy (EM), and a consensus model of its central framework has emerged (Fig. 2). Accordingly, the vertebrate NPC exhibits an 8-fold symmetric (i.e., perpendicular to the plane of the NE) tripartite architecture with a total mass of ~125 MDa. Its ~55 MDa central framework is a ring-like assembly built of eight multi-domain spokes consisting of two roughly identical halves each so that its asymmetric unit (i.e., one half-spoke) represents one 16th of its mass or roughly the size of a ribosome. This central framework is sandwiched between a ~32 MDa cytoplasmic ring and a ~21 MDa nuclear ring. From the cytoplasmic ring eight short, kinky fibrils emanate, whereas the nuclear ring anchors a basket (or fishtrap), assembled from eight thin, ~50 nm long filaments joined distally by a 30- to 50-nm-diameter ring. The ring-like, ~822-symmetric central framework embraces the central pore of the NPC which acts as a gated channel. The central pore is often plugged with a distinct particle, called central plug or transporter, of highly variable appearance whose molecular architecture and functional significance remain to be established.

2006-04-09 19:54:19 補充：

Ha...I love 棒棒糖, please mail to me...my address is BIND122, 1203 W. State Street, West Lafayette, IN47907. Thankx.

Source(s): from Tiger & Scrippts Institute

Answer 2

兩位很謝謝～

有機會請你們吃心平氣和棒棒糖

謝謝Ｔｉｇｅｒ的用心

也謝謝ＤＪ的體貼（我英文也不好呵呵）

再次謝謝兩位囉！

Answer 3

核孔的構造

圖片參考：http://www.scripps.edu/~stoffler/proj/NPC/NPC_whit...

此圖取自http://www.scripps.edu/~stoffler/proj/NPC/npc.html...

2006-04-09 17:53:18 補充：

To Tiger:我沒有複製過你的答案，我都是自己打和自己找資料的。你的答案在我貼文前我還沒過目過，我是在貼文後才再仔細看的。

2006-04-09 17:54:57 補充：

很抱歉，我搜尋到的圖剛好和你的圖是同一個出處。(剛剛才發現，Sorry！)

2006-04-09 18:02:52 補充：

起先我覺得整篇英文，又幾乎是純文字，我覺得這樣說不清楚，逕自找了結構圖貼上並且註明核孔成分，事後經Tiger提醒，才發現圖片出處相撞。

這次是我的疏失，未在仔細閱讀Tiger的文章後才決定發表文章的需要性，希望發問者能以Tiger的解答優先為最佳解答。

2006-04-09 18:08:35 補充：

我希望能這次能以Tiger的答案為最佳解答。

2006-04-09 18:42:26 補充：

即使是到了大學，還是對英文文章很無力，所以才會連看都還沒看就貼文。

也因此導致這次的失誤......Orz

(真的很對不起Tiger大大)

Source(s): 大學普生