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2007年12月13日Nature中文摘要
封面故事: 关于P-型ATP酶的一组研究论文
The structural basis of calcium transport by the calcium pump
P-型ATP酶是对所有真核生物和很多原核生物具有根本重要性的阳离子泵。本期
Nature上三篇论文介绍了关于这一超级家族关键成员的结构及功能研究。本期封
面所示为钠离子和钾离子泵的结构,是由Morth等人在本期杂志上以3.5埃的分辨
率描述的,同时还刊登了J. C. Skou关于其50年前发现依赖于钠离子和钾离子的
ATP酶活性的原始笔记。这篇论文显示了与钾相结合的状态,同时还暗示了一种
依赖于电压的调控基础。这些结果部分是通过与Skou所做实验相似的动能实验获
得的。Olesen等人介绍了肌质网Ca2+-ATP酶(钙泵)的新的晶体结构,同时还有
关于功能的研究工作,并且最终呈现了关于钙运输的一个完整机制。在植物和真
菌中,细胞离子平衡状态和膜势是由胞质膜H+-ATP酶(另一种P-型ATP酶)提供
动力的。Pedersen等人介绍了它的X-射线结构,提供了关于它是如何沿一个陡峭
的电化学梯度来泵输质子的有关线索。(Articles pp. 1036, 1043; Letter p.
1111; News & Views)


哺乳动物演化并非走直线(The descent of mammals)
Transformation and diversification in early mammal evolution
哺乳动物的演化经常被说成是一个线性过程,关键特征是从作为其祖先的爬行类
动物的相关特征发展来的,而且是不断增添的:如中耳是从颌关节演化来的,臼
齿是从爬行类简单的尖齿演化来的。 但正如罗哲西在一篇Review Article中所
反映的那样,大量最近发现的化石彻底改变了这一观点。哺乳动物的演化所走过
的远远不是一条直线,而是一个复杂的、分叉的网络,其中有若干个死胡同:哺
乳动物特征在几个单独的支系是重复演化的,有时这些特征还会丢失。(Review
Article p. 1011)


“银河系”的内“晕”和外“晕”(Halo, halo)
Two stellar components in the halo of the Milky Way
“银河系”银盘之外的区域(称作“晕”)过去长时间被认为是一个均一的实
体,由古老恒星组成。但最近对“晕”内少量天体所做分析表明,它们并不是由
同一类天体组成的。现在,根据来自超过2万颗恒星的光谱数据,研究人员发现
“晕”是由两个大体上交叠的结构成分组成的:内“晕”和外“晕”。内“晕”
与整个“银河系”在同一方向上缓慢转动;外“晕”向相反方向转动,比氦重的
元素含量相对降低。内“晕”可能是由一系列耗散性合并过程形成的,而外
“晕”则是通过无耗散的过程及原始银河系星团的潮汐式破坏形成的。
(Article p. 1020)


核小体的位置及定位机制(Jostling for position)
Chromatin remodelling at promoters suppresses antisense transcription
核小体(染色质的基本单元)的定位对很多依赖于DNA的过程有深远影响,但细
胞中所涉及的定位机制却并不是特别清楚。现在,研究人员利用野生型细胞和染
色质调控因子Isw2的一个突变体,确定了核小体在酿酒酵母整个基因组中的位
置。该调控因子在基因的5′端和3′端发挥作用,从而在数百个基因间区域增加
核小体密度。重要的是,Isw2通过抑制异常的非编码转录来帮助从相对于启动子
的正确取向开始进行转录。(Article p. 1031; News & Views)


“卡西尼”获得土星环流图像(Saturn’s other ring)
A dynamic, rotating ring current around Saturn
关于在距地面较高处有一个由束缚的粒子组成的环流(ring current)围绕地球
的观点首次出现在20世纪早期。这个观点被证明是正确的,对该环流及其组成的
测量工作于 1957年进行。后来人们在木星上也发现了不同性质的环流,并且推
测土星也有这种环流。现在,安装在“卡西尼”探测器上的磁圈成像仪器获得了
土星环流的图像。该环流是高度可变的,具有强经向不对称性,与该行星几乎成
刚性共同转动。这与地球的环流形成对比,后者没有自转调制,且最初的不对称
性取决于局部效应。(Letter p. 1050)


海上异常波浪产生原理研究(Catch a freak wave)
Optical rogue waves
水手们几个世纪以前就知道,异常的巨大波浪似乎能够毫无征兆地就出现在海洋
上。碰上这种“恶棍”波浪的可能性最近被发现远远大于从传统波幅统计中所能
预计的程度。为了解这种事件的物理原理,Solli等人在一个光学系统中对“恶
棍”波浪的概念进行了研究。利用一个新的实时探测方法,他们研究了一个体系
(基于一种具有显微结构的光纤),该体系能够暴露出极陡的大光波,它们是因
一组几乎相同的光脉冲的注入而产生的罕见结果。这种“恶棍”光波是当随机噪
音以一定的频率变化、在一个明确限定的时间窗口内扰动最初平滑的脉冲时产生
的。(Letter p. 1054; News & Views)


超导“胶”的起源问题(Superconducting glue)
A distinct bosonic mode in an electron-doped
high-transition-temperature superconductor
也许在高温超导领域目前争论最多的问题是将电子结合成超导对的超导“胶”的
微观起源问题。两种主要观点分别是晶格振动(声子)和自旋激发。还有一种可
能性,那就是,电子是在没有调控因子的情况下成对的。Niestemski等人报告了
被称为PLCCO的电子掺杂的超导体的在空间上可以分辨的、并且可以重复的光
谱,它显示在该材料的电子激发中有一个位于10.5 ± 2.5 meV处的集体模式。
这个发现与该模式的电子(和/或磁?)起源是一致(也可能与超导“胶”观点
是一致的),也与在该过程中涉及自旋激发而不是声子的观点是一致的。
(Letter p. 1058)


决定热带气旋强度的因素(Remote control of cyclones)
Effect of remote sea surface temperature change on tropical cyclone
potential intensity
关于热带气旋活动对全球变暖的响应问题我们很不了解。科学家经常假设,海洋
表面温度越高,越有利于气旋形成和加强,但事实可能并不是这样,因为其中还
涉及很多其他因素。Gabriel Vecchi和Brian Soden对海洋表面温度变化与一种
被称为“热带气旋潜在强度”的指标(该指标为气旋强度提供一个上限)之间的
关系进行了研究。他们发现,潜在强度的变化与变暖的区域结构密切相关,而不
是与局部海洋表面温度密切相关——比热带平均温度更高的区域以潜在强度增加
为特征,反之亦然。这说明,热带气旋活动对气候自然变异(往往涉及海洋表面
温度局部化的变化)的响应可能大于对由温室气体诱导的更为一致的变暖模式的
响应。(Letter p. 1066)


女性脊柱的特别之处(The mother load)
Fetal load and the evolution of lumbar lordosis in bipedal hominins
背痛是人们请病假的一个重要原因,是直立行走(人类及其祖先不同于其他动物
的一个鲜明特征)所带来的困难的证明。由于在人类历史及史前的大部分时间,
成年妇女都把很多时间花在怀孕或哺乳上,所以妇女还有另外一个演化问题。怀
孕因不断改变身体的重心而使得直立行走的不稳定性变得更加严重。Whitecombe
等人对能够平衡胎儿负荷的、女性脊柱所特有的那些解剖学上的适应性特征进行
了详细分析,发现直立行走的南猿(而不是非直立行走的黑猩猩)也有类似的适
应性特征。(Letter p. 1075; www.nature.com/podcast


控制“转座子”的一种办法(How mutator bacteria arise)
Coevolution with viruses drives the evolution of bacterial mutation
rates
在变化中的环境中进行的细菌培养有时会积累突变率增大的“转座子”
(mutator)品系,可能会增强它们进行适应性演化的潜力。这种情况经常发生
在临床条件下。如果“转座子”要长久存在,它们就需要一个一致变化的环境。
与寄生体(如病毒)共同演化是能够提供这种环境的一个情形。现在,用假单胞
菌所做的实验表明,与一种自然出现的噬菌体共同演化会明显提高细菌突变率,
导致噬菌体绝灭概率增高。因此,以噬菌体种群为控制目标可能是在临床感染环
境中削弱对“转座子”选择性的一种办法。(Letter p. 1079)


疟原虫在人体中的三种存在状态(Triple identity for malaria)
Distinct physiological states of Plasmodium falciparum in
malaria-infected patients
疟疾研究中的一大困惑是,被感染儿童临床症状很多——从轻微流感症状到昏迷
和死亡都有。现在,对从人类患者身上分离出的疟疾寄生虫所进行的一次大型转
录分析,揭示了造成这种差异的一个可能的线索。镰刀性疟原虫在人类宿主身上
以三种不同生理状态存在,它们可以被分别描述为一种积极生长状态、一种对饥
饿的反应状态和一种环境压力反应状态。这一发现对于用目前的药物进行治疗以
及对于未来药物和疫苗的开发都具有重要意义。(Letter p. 1091; News &
Views)


一种病毒微RNA能够模仿miR-155(RNA MIMIC)
A viral microRNA functions as an orthologue of cellular miR-155
一些病毒微RNA已知会与宿主细胞mRNA结合,以阻断转录或诱导它们的退化。现
在,来自与 Kaposi肉瘤相关的疱疹病毒的一种微RNA已被发现能够模仿一种普遍
存在的细胞微RNA(即miR-155)的活性。这一小型RNA的病毒版本(它与真正的
miR-155有很大的同源性)可能是为了利用宿主B-细胞中一个以前已经存在的基
因调控通道而形成的。(Letter p. 1096)

----------------------
NEWS AND VIEWS
----------------------
Photonics: Rogue waves surface in light pp953 - 954
How do the freak waves that haunt seafarers' nightmares arise? We
don't know, is the short answer ― but the discovery of a similar
phenomenon in optical waves might assist in getting to the bottom of
the mystery.
Dong-Il Yeom and Benjamin J. Eggleton
doi:10.1038/450953a
http://www.nature.com/nature/journal/v450/n7172/full/450953a.html

50 & 100 Years Ago p954
doi:10.1038/450954a
http://www.nature.com/nature/journal/v450/n7172/full/450954a.html

Malaria: Differential parasite drive pp955 - 956
Our knowledge of the inner workings of malaria parasites comes largely
from lab-based studies. But parasites growing in humans may have
greater metabolic flexibility than those growing in Petri dishes.
Giel G. van Dooren and Geoffrey I. McFadden
doi:10.1038/450955a
http://www.nature.com/nature/journal/v450/n7172/full/450955a.html

Astronomy: Dim view of past clashes pp956 - 957
Simulations indicate that faint galaxies of a seemingly tranquil class
were born in violent cosmic encounters. This would be good news for
the prevailing model of how the Universe is constructed.
Curtis Struck
doi:10.1038/450956a
http://www.nature.com/nature/journal/v450/n7172/full/450956a.html

Structural biology: Ion pumps made crystal clear pp957 - 959
The function of every cell in our bodies depends on the work of
proteins known as ion pumps. Several new crystal structures cast fresh
light on how three different pumps deal with their distinct cargoes of
ions.
David C. Gadsby
doi:10.1038/450957a
http://www.nature.com/nature/journal/v450/n7172/full/450957a.html

Molecular biology: Genome under surveillance pp959 - 960
Decoding the information stored in DNA requires an intricate balance
between processes that turn gene expression on or off. A protein that
influences the packaging of DNA regulates this balance genome-wide.
Karen M. Arndt
doi:10.1038/450959a
http://www.nature.com/nature/journal/v450/n7172/full/450959a.html

Materials chemistry: Cool conditions for mobile ions pp960 - 961
A complex iron oxide has been made that has an unusual crystal
structure suggesting that the oxide ions are surprisingly mobile. This
finding could pave the way to other metal-oxide materials with useful
properties.
Michael A. Hayward and Matthew J. Rosseinsky
doi:10.1038/450960a
http://www.nature.com/nature/journal/v450/n7172/full/450960a.html

CORRESPONDENCE
Correction p961
doi:10.1038/450961a
http://www.nature.com/nature/journal/v450/n7172/full/450961a.html

Obituary: Gene H. Golub (1932-2007) p962
Mathematician and godfather of numerical analysis.
Lloyd N. Trefethen
doi:10.1038/450962a
http://www.nature.com/nature/journal/v450/n7172/full/450962a.html

----------------------
INSIGHT
----------------------
INTRODUCTION
Proteins to proteomes p963
Tanguy Chouard and Joshua Finkelstein
doi:10.1038/450963a
http://www.nature.com/nature/journal/v450/n7172/full/450963a.html

REVIEW ARTICLE
Dynamic personalities of proteins pp964 - 972
Katherine Henzler-Wildman and Dorothee Kern
doi:10.1038/nature06522
Abstract:
http://www.nature.com/nature/journal/v450/n7172/abs/nature06522.html
Article:
http://www.nature.com/nature/journal/v450/n7172/full/nature06522.html

The molecular sociology of the cell pp973 - 982
Carol V. Robinson, Andrej Sali and Wolfgang Baumeister
doi:10.1038/nature06523
Abstract:
http://www.nature.com/nature/journal/v450/n7172/abs/nature06523.html
Article:
http://www.nature.com/nature/journal/v450/n7172/full/nature06523.html

The origin of protein interactions and allostery in
colocalization pp983 - 990
John Kuriyan and David Eisenberg
doi:10.1038/nature06524
Abstract:
http://www.nature.com/nature/journal/v450/n7172/abs/nature06524.html
Article:
http://www.nature.com/nature/journal/v450/n7172/full/nature06524.html

The biological impact of mass-spectrometry-based proteomics pp991
- 1000
Benjamin F. Cravatt, Gabriel M. Simon and John R. Yates III
doi:10.1038/nature06525
Abstract:
http://www.nature.com/nature/journal/v450/n7172/abs/nature06525.html
Article:
http://www.nature.com/nature/journal/v450/n7172/full/nature06525.html

Reaching for high-hanging fruit in drug discovery at protein-protein
interfaces pp1001 - 1009
James A. Wells and Christopher L. McClendon
doi:10.1038/nature06526
Abstract:
http://www.nature.com/nature/journal/v450/n7172/abs/nature06526.html
Article:
http://www.nature.com/nature/journal/v450/n7172/full/nature06526.html

----------------------
REVIEW
----------------------
Transformation and diversification in early mammal evolution pp1011
- 1019
A host of recently discovered fossils shows that mammal evolution was
less a linear tale than a complex bush, in which mammalian feature
evolved repeatedly in separate lineages, and were sometimes lost.
Zhe-Xi Luo
doi:10.1038/nature06277
Abstract:
http://www.nature.com/nature/journal/v450/n7172/abs/nature06277.html
Article:
http://www.nature.com/nature/journal/v450/n7172/full/nature06277.html

----------------------
ARTICLES
----------------------
Two stellar components in the halo of the Milky Way pp1020 - 1025
The halo of the Milky Way is clearly divisible into two broadly
overlapping structural components, an inner and an outer halo. While
the inner halo has a modest net prograde rotation, the outer halo
exhibits a net retrograde rotation and a peak metallicity one third
that of the inner.
Daniela Carollo et al.
doi:10.1038/nature06460
Abstract:
http://www.nature.com/nature/journal/v450/n7172/abs/nature06460.html
Article:
http://www.nature.com/nature/journal/v450/n7172/full/nature06460.html

Molecular code for transmembrane-helix recognition by the Sec61
translocon pp1026 - 1030
How the Sec translocon recognises transmembrane α-helices in newly
synthesised proteins is revealed by the analysis of a large number of
hydrophobic segments and presentation of a quantitative analysis of
the position-dependent contribution of efficiency of membrane
insertion for all amino acids. The results support the idea that
recognition of transmembrane helices by the Sec translocon is a
lipid-partitioning process.
Tara Hessa et al.
doi:10.1038/nature06387
Abstract:
http://www.nature.com/nature/journal/v450/n7172/abs/nature06387.html
Article:
http://www.nature.com/nature/journal/v450/n7172/full/nature06387.html

Chromatin remodelling at promoters suppresses antisense
transcription pp1031 - 1035
The yeast chromatin remodelling complex Isw2 repositions nucleosomes
that are adjacent to promoter regions and enforces directionality on
transcription by preventing inappropriate transcription initiation
from cryptic sites.
Iestyn Whitehouse, Oliver J. Rando, Jeff Delrow and Toshio Tsukiyama
doi:10.1038/nature06391
Abstract:
http://www.nature.com/nature/journal/v450/n7172/abs/nature06391.html
Article:
http://www.nature.com/nature/journal/v450/n7172/full/nature06391.html

The structural basis of calcium transport by the calcium pump pp1036
- 1042
In plants and fungi, cellular ion homeostasis is powered by the proton
pump, a member of the P-type ATPase family. The first X-ray structure
of the H+-ATPase is presented, and insight into the mechanism by which
protons are transported against an electrochemical gradient is
provided
Claus Olesen et al.
doi:10.1038/nature06418
Abstract:
http://www.nature.com/nature/journal/v450/n7172/abs/nature06418.html
Article:
http://www.nature.com/nature/journal/v450/n7172/full/nature06418.html

Crystal structure of the sodium-potassium pump pp1043 - 1049
Relatively little is known about the mechanisms that underlie the
active transport of ions by Na+,K+-ATPase. A 3.5 A X-ray structure of
this fundamental protein is presented, revealing the two binding sites
for potassium.
J. Preben Morth et al.
doi:10.1038/nature06419
Abstract:
http://www.nature.com/nature/journal/v450/n7172/abs/nature06419.html
Article:
http://www.nature.com/nature/journal/v450/n7172/full/nature06419.html

----------------------
LETTERS
----------------------
A dynamic, rotating ring current around Saturn pp1050 - 1053
S. M. Krimigis et al.
doi:10.1038/nature06425
Abstract:
http://www.nature.com/nature/journal/v450/n7172/abs/nature06425.html
Article:
http://www.nature.com/nature/journal/v450/n7172/full/nature06425.html

Optical rogue waves pp1054 - 1057
The concept of rogue waves in an optical system is investigated by
utilizing a new real-time detection technique to study a system that
exposes extremely steep, large optical waves as rare outcomes from
injection of a population of almost-identical optical pulses. Analysis
of these results finds that the optical rogue waves arise when random
noise perturbs the initially smooth pulses with a certain frequency
shift and within a well-defined time window.
D. R. Solli, C. Ropers, P. Koonath and B. Jalali
doi:10.1038/nature06402
Abstract:
http://www.nature.com/nature/journal/v450/n7172/abs/nature06402.html
Article:
http://www.nature.com/nature/journal/v450/n7172/full/nature06402.html

A distinct bosonic mode in an electron-doped
high-transition-temperature superconductor pp1058 - 1061
A bosonic excitation (mode) at energies 10.5 ± 2.5 meV in the
electron doped superconductor Pr0.88LaCe0.12CuO4 (PLCCO) is reported.
The analysis of this indicates an electronic origin of the mode
consistent with spin excitations rather than phonons.
F. C. Niestemski et al.
doi:10.1038/nature06430
Abstract:
http://www.nature.com/nature/journal/v450/n7172/abs/nature06430.html
Article:
http://www.nature.com/nature/journal/v450/n7172/full/nature06430.html

Infinite-layer iron oxide with a square-planar coordination pp1062
- 1065
The synthesis of SrFeO2, a new compound bearing a square-planar oxygen
coordination around Fe2+, is shown. SrFeO2 is isostructural with
'infinite layer' cupric oxides, and exhibits a magnetic order far
above room temperature.
Y. Tsujimoto et al.
doi:10.1038/nature06382
Abstract:
http://www.nature.com/nature/journal/v450/n7172/abs/nature06382.html
Article:
http://www.nature.com/nature/journal/v450/n7172/full/nature06382.html

Effect of remote sea surface temperature change on tropical cyclone
potential intensity pp1066 - 1070
The relationship between changes in sea surface temperature and a
measure called 'tropical cyclone potential intensity', which provides
an upper bound on cyclone intensity, is explored. It is found that
changes in potential intensity are closely related to the regional
structure of warming, rather than local sea surface temperature ―
regions that warm more than the tropical average are characterized by
increased potential intensity, and vice versa.
Gabriel A. Vecchi and Brian J. Soden
doi:10.1038/nature06423
Abstract:
http://www.nature.com/nature/journal/v450/n7172/abs/nature06423.html
Article:
http://www.nature.com/nature/journal/v450/n7172/full/nature06423.html

Dynamics of Mid-Palaeocene North Atlantic rifting linked with European
intra-plate deformations pp1071 - 1074
Soren B. Nielsen, Randell Stephenson and Erik Thomsen
doi:10.1038/nature06379
Abstract:
http://www.nature.com/nature/journal/v450/n7172/abs/nature06379.html
Article:
http://www.nature.com/nature/journal/v450/n7172/full/nature06379.html

Fetal load and the evolution of lumbar lordosis in bipedal
hominins pp1075 - 1078
Pregnancy makes the instability of upright walking even worse by its
constant shifting the centre of gravity. The anatomical adaptations
peculiar to female spines that balance the fetal load are detailed,
and show that our australopithecine ancestors had much the same
adaptations.
Katherine K. Whitcome, Liza J. Shapiro and Daniel E. Lieberman
doi:10.1038/nature06342
Abstract:
http://www.nature.com/nature/journal/v450/n7172/abs/nature06342.html
Article:
http://www.nature.com/nature/journal/v450/n7172/full/nature06342.html

CLOCK-mediated acetylation of BMAL1 controls circadian function pp1086
- 1090
The circadian regulator CLOCK has histone acetyltransferase (HAT)
activity that contributes to chromatin-remodelling events during
circadian control of gene expression. Here, CLOCK is shown to
acetylate its heterodimerization partner BMAL1, a step which
facilitates recruitment of CRY1 and promotes transcriptional
repression.
Jun Hirayama et al.
doi:10.1038/nature06394
Abstract:
http://www.nature.com/nature/journal/v450/n7172/abs/nature06394.html
Article:
http://www.nature.com/nature/journal/v450/n7172/full/nature06394.html

A viral microRNA functions as an orthologue of cellular miR-155 pp1096
- 1099
Viral microRNAs have been shown to downregulate complementary viral
mRNA targets and to bind to 3′ untranslated regions of host cell
mRNAs to prevent their translation or induce their degradation. This
paper shows that viral miRNAs can also function as orthologues of
cellular miRNAs and downregulate the expression of cellular mRNAs via
target sites that may be evolutionary conserved.
Eva Gottwein et al.
doi:10.1038/nature05992
Abstract:
http://www.nature.com/nature/journal/v450/n7172/abs/nature05992.html
Article:
http://www.nature.com/nature/journal/v450/n7172/full/nature05992.html

Crystal structure of the plasma membrane proton pump pp1111 - 1114
In plants and fungi, cellular ion homeostasis is powered by the proton
pump, a member of the P-type ATPase family. The first X-ray structure
of the H+-ATPase is presented, and insight into the mechanism by which
protons are transported against an electrochemical gradient is
provided.
Bjorn P. Pedersen et al.
doi:10.1038/nature06417
Abstract:
http://www.nature.com/nature/journal/v450/n7172/abs/nature06417.html
Article:
http://www.nature.com/nature/journal/v450/n7172/full/nature06417.html
 
    
 


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