|
  
- 积分
- 1133
- 威望
- 1133
- 包包
- 4372
|
附上原文：
! J9 Y2 h( M) j; y----------------------
$ V6 N3 h7 A+ R' m9 ^" }ARTICLES
8 F- q0 \2 k4 w( x3 }" b4 {----------------------3 R6 L9 b& y- j
Light-avoidance-mediating photoreceptors tile the Drosophila larval
0 r$ S' e( l3 N f+ p5 dbody wall pp921 - 926
3 g Q7 X) }* E) {# oLight sensing outside the eyes is common in many animals but is
% W: C4 p) F: A+ O' eusually confined to specialized organs. Here, the entire body wall of
5 G$ j3 c0 L3 A5 }1 E2 ithe fruitfly larva is found to be tiled with blue- and ultraviolet- H% Y0 G) e& H$ C. S4 Y( W
light sensing neuronal dendrites, which are essential for the larva's
& x1 |7 o! P: l1 N) ^innate light-avoidance behaviour. The phototransduction machinery used
( W4 \8 y1 P% j6 I# `by these neurons is distinct from other Drosophila photoreceptor 0 _. G3 ?4 {" N. |8 t% l
molecules but similar to a system recently identified in nematode
$ I3 Y) _$ a; E% _2 ~: ^neurons.
4 z! g$ B& H9 J) O, a$ JYang Xiang et al.
: e/ j1 P2 ?; ?+ Y. Xdoi:10.1038/nature095761 K4 u' u; l2 n+ g& `" _" h# i
Abstract: http://www.nature.com/nature/jou ... bs/nature09576.html
6 n5 L. `' L7 F2 J4 dArticle: http://www.nature.com/nature/jou ... ll/nature09576.html" B: {2 l$ U0 @& ?2 q; O _+ o
4 I" K+ o; ~; g0 L$ _5 G) n
TRIM24 links a non-canonical histone signature to breast cancer pp927
5 a8 |2 |2 }$ L8 Z4 b- 932+ X R7 A) u$ `. \' K- f4 x
A crystal structure of the tandem PHD and bromodomain regions of the 7 Z8 S% |2 g; Y7 o: B% i
transcription and chromatin regulator TRIM24 reveals combinatorial 5 w4 p7 q' |6 v; w
recognition of dual marks on the histone H3 tail. TRIM24 is involved 1 Z' Y; P* h" N4 L. z1 q H
in activation of oestrogen-dependent genes and is aberrantly expressed ' V- o+ `1 ^1 m" c
in breast cancer.* w( f& C: D/ ]* |6 r X, ~+ n6 O1 O
Wen-Wei Tsai et al.
0 Y) f, }; ]( C1 Q: I! N3 tdoi:10.1038/nature09542
& T1 v: {, ~+ SAbstract: http://www.nature.com/nature/jou ... bs/nature09542.html3 b) K" e6 b! F
Article: http://www.nature.com/nature/jou ... ll/nature09542.html# ~6 ?% \# K- w% d; G2 i! v) {5 H1 a
. c9 d# X& B5 I4 Q, F
CRTC3 links catecholamine signalling to energy balance pp933 - 939
. }+ @2 d# `6 J( Aβ-adrenergic receptor signalling in adipocytes stimulates energy 2 e# m2 M" X4 P+ |% j) @+ R
expenditure via cAMP-dependent increases in lipolysis and fatty-acid & {' g. E) N+ Y# b5 p b& e. H
oxidation, and this signalling mechanism is thought to be disrupted in ' _" ^) l7 Z, W; `7 H
obesity. Here, the cAMP-responsive CREB coactivator Crtc3 is shown to
+ J! k0 e2 [* K4 r( m4 v+ x6 y& X8 hpromote obesity in mice by attenuating β adrenergic receptor ' C x p- J: B& i1 A$ a
signalling in adipose tissue.
. h( j4 a4 O- h' d. c) y5 eYoungsup Song et al.( }* _9 P1 a. \; u& X' D
doi:10.1038/nature09564* l! {! ]0 a5 R- Q
Abstract: http://www.nature.com/nature/jou ... bs/nature09564.html
4 B- b5 k" _' R7 Z6 N0 O" J5 I$ b: a& JArticle: http://www.nature.com/nature/jou ... ll/nature09564.html
( H$ D1 m' g3 A+ \) z0 Z& E$ z+ | O, B
----------------------
8 r4 z8 l8 w! k9 o; Q$ tLETTERS
* X6 \* x' ]) J4 z----------------------
, L) V/ s+ g. e4 V' b1 ]A substantial population of low-mass stars in luminous elliptical " W6 K) e- }8 s0 ]$ }9 E8 V
galaxies pp940 - 9422 O# u5 m6 G3 K% t; O! r3 m5 d
The stellar initial mass function describes the mass distribution of . G0 j- g% r8 V5 q B
stars at the time of their formation. This study reports observations % J! }3 V9 A* b6 m$ O' N
of the Na I doublet and the Wing-Ford molecular FeH band in the
' I4 J3 {0 V( B0 R) ispectra of elliptical galaxies. These lines are strong in stars with
% I5 i) a- ?" l& A! y Kmasses6 d2 T0 c/ _# f# f' `# ^8 n% N
Pieter G. van Dokkum and Charlie Conroy
N8 H1 Q% T5 E- ?" ?7 _doi:10.1038/nature09578# N( q! W k- @, J# R
Abstract: http://www.nature.com/nature/jou ... bs/nature09578.html- r9 d! Y: n. p6 E4 ?
Article: http://www.nature.com/nature/jou ... ll/nature09578.html8 A- R, B9 j c: \- |: X ?7 E: A
4 ~8 G; h( h! g" o
Origin of Saturn’s rings and inner moons by mass removal from a lost
/ W, @$ ^$ d" m! ]3 rTitan-sized satellite p943$ C* P( ?" k+ q8 a. n8 v
Saturn's rings are more than 90–95% water ice, which implies that ( @/ {' r2 s: a
initially they were almost pure ice because they are continually
4 l, I* c) b3 l8 m7 W y V9 `) H* e, apolluted by rocky meteoroids. Saturn has only one large satellite,
3 v! z& ^$ G. Z0 i% ~: y" Z- U: @Titan, whereas Jupiter has four large satellites; additional large
# k, ^) I" i% N# ]9 @' X3 e4 p5 csatellites probably existed originally but were lost as they spiralled 0 }2 D2 J8 a# W
into Saturn. Now, numerical simulations of the tidal removal of mass
- V- W' P$ I+ ~$ I" B+ Rfrom a differentiated, Titan sized satellite as it migrates inward * P2 s( a9 l' U0 W5 w/ V
towards Saturn are reported. Planetary tidal forces preferentially
3 e) t; f. E5 w4 `0 B9 kstrip material from the satellite's outer icy layers, while its rocky : ^% g d" A" t2 ?6 v8 W- f
core remains intact and is lost to collision with the planet. The
, W% A# M7 u6 U. U: S' vresult is a pure ice ring.
. ~, f0 k# n0 I& ^9 ?: tRobin M. Canup+ |% h- [! L& @7 I
doi:10.1038/nature09661
9 j8 Q, T W2 r# Y% B! FAbstract: http://www.nature.com/nature/jou ... bs/nature09661.html6 m% ~* o* u0 S2 P3 G
Article: http://www.nature.com/nature/jou ... ll/nature09661.html# b) k5 D# W6 |
. k5 `3 \& |+ {# L$ b; u% ]Pleats in crystals on curved surfaces pp947 - 951
i0 q8 D& F: [Hexagons can easily tile a flat surface, but not a curved one. Defects : c3 [6 ?/ T# O
with topological charge (such as heptagons and pentagons) make it ( z$ o1 u- s$ H- i3 u9 E1 \
easier to tile curved surfaces, such as soccer balls. Here, a new type & i9 U6 j: Q: c4 X
of defect is reported that accommodates curvature in the same way as
; l/ G4 K) `" {" J t; p6 Hfabric pleats. The appearance of such defects on the negatively curved
' `3 c' @1 s+ Hsurfaces of stretched colloidal crystals are observed. The results
. h. x1 K' n, {# f6 }) Fwill facilitate the exploration of general theories of defects in
$ E5 b2 M* g7 k! hcurved spaces, the engineering of curved structures and novel methods 3 c$ `( c" h8 ?
for soft lithography and directed self-assembly.
. @9 I; s/ k+ o) UWilliam T. M. Irvine, Vincenzo Vitelli and Paul M. Chaikin
2 T, U$ }" m, i- rdoi:10.1038/nature09620
! Q$ q% }+ R; N* \8 y& f' P1 tAbstract: http://www.nature.com/nature/jou ... bs/nature09620.html- ^" ]0 V4 E% S5 w$ s
Article: http://www.nature.com/nature/jou ... ll/nature09620.html
# V% i8 y5 S( {: s) J) [! V E+ h( S3 J( A9 m
Tidal dissipation and the strength of the Earth’s internal magnetic
/ r* m8 S% K. @7 afield pp952 - 954
9 ~- \4 q) Z* R$ I5 tHere, an indirect estimate for the magnetic field strength within the / c7 v% K: k8 L' Q" S7 t
Earth's core from measurements of tidal dissipation is presented. ! z) I* n2 Y% ?/ [' d! H0 n
Previously reported evidence of anomalous dissipation in the Earth's
3 x! C7 X; x; qnutations can be explained with a core-averaged field of 2.5 mT,
' A* |! y% X' m/ D$ X; ueliminating the need for high fluid viscosity or a stronger magnetic
9 {: l5 d, r6 v. v6 [! t3 {; ~field at the inner-core boundary.
1 ^1 i3 h9 X# ]. C4 \( B" r e8 tBruce A. Buffett0 H3 N2 V7 I+ Q
doi:10.1038/nature09643 Q7 |2 l! w( M
Abstract: http://www.nature.com/nature/jou ... bs/nature09643.html
6 _$ e ^$ W0 `8 KArticle: http://www.nature.com/nature/jou ... ll/nature09643.html
! e) A3 m, Y4 f, B7 ^, C3 E8 T' C, I! j. ]- e9 I" y3 _2 `
Greenhouse gas mitigation can reduce sea-ice loss and increase polar
; Z5 V$ X. h' b1 l% obear persistence pp955 - 958
$ k1 F! l* w6 t) O% S- tThe dramatic loss of Arctic sea ice with climate change has led to the 8 X; f1 O9 { q
prediction of a tipping point beyond which ice loss is irreversible
) U! Z* o: W2 {( wand polar bear habitat will be catastrophically lost. By contrast, + v1 v9 i6 n4 c' x2 |4 @& P
this study shows a linear relationship between temperature and sea-ice 4 _2 ^. `5 }' }2 W! I( ~* n9 L4 B
coverage that overcomes the albedo effect that would cause a tipping & h$ u0 t# k# L
point. As a result, reducing greenhouse gas emissions can have a % q# X7 C2 j( S' V8 M0 U: h) T
positive effect on polar bear populations.: E2 Q9 [; X8 k: ?$ X# @5 `
Steven C. Amstrup et al.: K3 C6 w7 T# _$ P3 G( P, V
doi:10.1038/nature09653* h! B$ U- }" f% s
Abstract: http://www.nature.com/nature/jou ... bs/nature09653.html7 g6 M3 J' B1 `) r
Article: http://www.nature.com/nature/jou ... ll/nature09653.html
5 E- p8 n* i) ^+ S! ~3 j3 J( v1 k6 @* _; Z9 C
Intercalation of a new tier of transcription regulation into an . e b, F$ W$ f4 H$ F; O
ancient circuit pp959 - 963/ x' z3 a4 p% j
How new phenotypes can be introduced during evolution without losses 9 `2 F! h& q9 o, v* e: a
of fitness remains largely unexplained at the molecular level. By
w) y0 g; } F1 M3 J7 H4 h* dcomparing the molecular details of a well known process — mating type
* d; M L) x3 | Q1 n! S1 |determination — across a large diversity of yeast species, the & C" `- P- a$ m" V" R4 D5 S7 Q ?4 \
network rewiring event of the intercalation of a new level of gene
( B& \* @0 A2 Q7 ctranscription control into an ancient regulatory circuit is shown,
; Y& z- ]7 V8 w# wwhich allowed for the creation of a new phenotype — taking food 6 `) F+ s z L* A# u/ D: {* L& j
availability into account when deciding to mate.
9 a2 a) x: o; b2 nLauren N. Booth, Brian B. Tuch and Alexander D. Johnson
+ T; ^6 E0 i0 D1 wdoi:10.1038/nature095605 }5 j- q, R* V# M. }
Abstract: http://www.nature.com/nature/jou ... bs/nature09560.html$ `5 ~; ]$ w- D: g. Y. Q+ L
Article: http://www.nature.com/nature/jou ... ll/nature09560.html
, h6 E6 w; T; y
% o5 a; R% T) X4 K9 ^Noise correlations improve response fidelity and stimulus encoding
. O9 A% H! f7 ]4 M: U8 Upp964 - 967
t' z/ _! \2 AThis study introduces a novel recording technique for simultaneously
( X7 t9 {* j. @8 F |! v$ Vmeasuring excitatory and inhibitory conductances of retinal ganglion ! s1 J/ a# ]1 s4 N: Q
cells to show that excitatory and inhibitory inputs are strongly + l0 Z* U2 D4 V$ d( y d, C( I
correlated, thereby cancelling each other. Furthermore, dynamic clamp . [4 S' C5 Z) O1 o3 C3 l' u' q4 F
is used to introduce these conductance changes into the cell with or 9 r6 m1 i- w. v4 u F
without correlations, and it is found that, as predicted by 9 i1 {" V+ O) y* e/ n/ P- D8 v9 L
theoretical work, correlations significantly increase reliability of 6 `; _. Z# b5 L3 e6 [+ p/ ~
the spiking response.' J- E/ j+ M* c8 I5 t: I t8 R
Jon Cafaro and Fred Rieke* x8 Z! o. |7 i' \
doi:10.1038/nature095709 O% O% ~& B l5 y! ]4 Q7 Y/ m
Abstract: http://www.nature.com/nature/jou ... bs/nature09570.html
@9 r) G8 E* V3 e5 \Article: http://www.nature.com/nature/jou ... ll/nature09570.html
. J" ^9 L6 E( X2 H/ b$ D- O
3 y3 A$ B6 e: _$ H+ h7 ]COT drives resistance to RAF inhibition through MAP kinase pathway * i, K2 }! t0 T; b; m( p
reactivation pp968 - 972
: K; L3 b2 s3 `3 RRecent data from early clinical trials in melanoma patients carrying
& M# D6 C h. B/ Fmutations in the B-RAF gene have shown promising results with the B- 3 Y* S% P- M( ?2 j
RAF kinase inhibitor PLX4032; however, many patients eventually
4 T1 a2 ]- W7 m* vdevelop resistance to this treatment. Two papers now uncover possible " U# |4 m0 u) ~+ v. d
mechanisms of resistance to PLX4032. One paper shows that upregulation
7 T# k% [# Q* ]. R- L( Gof MAP3K8 (which encodes COT) can confer resistance of melanoma cells
, I8 w+ U' t1 e& v5 c+ J3 Tto B-RAF inhibitors, whereas another paper found that melanomas can ?3 G- ]* Q2 C7 K. E
acquire resistance due to mutations of N-RAS or increased expression
1 K. v2 w ]5 ^) Mof PDGFRβ. Each of these resistance mechanisms seems to apply to at
6 _4 Y8 a# `% g( ~. `5 c3 tleast some patients on recent PLX4032 trial, whereas, surprisingly, so
+ m; ^$ y$ q* Nfar no secondary B-RAF mutations have been observed.
' V# k- P4 Q# r: L/ c- ]; iCory M. Johannessen et al.2 g" |0 T- Y7 i+ h9 c
doi:10.1038/nature09627
/ {/ i, y: ?6 @! AAbstract: http://www.nature.com/nature/jou ... bs/nature09627.html
" i9 L9 p3 f. j; @, U) y* _7 wArticle: http://www.nature.com/nature/jou ... ll/nature09627.html; p( s8 L9 T* c: {$ |7 C
) k/ D! m, \! ^- K) rMelanomas acquire resistance to B-RAF(V600E) inhibition by RTK or N- 5 K; n. v. g, e6 b5 i
RAS upregulation pp973 - 9777 N, y* L$ M* g$ m! Q) ^" g/ H5 S6 r
Recent data from early clinical trials in melanoma patients carrying ! u' m3 B6 T }" S2 }( _& G: o
mutations in the B-RAF gene have shown promising results with the B-
$ c# N# L& L" A2 e. w+ w BRAF kinase inhibitor PLX4032; however, many patients eventually 7 _1 M7 _8 R2 X* v7 d+ P* A
develop resistance to this treatment. Two papers now uncover possible
- {' [* ]5 b% l9 H2 y& Q+ _6 Wmechanisms of resistance to PLX4032. One paper shows that upregulation
, K: ]0 X1 ?) \of MAP3K8 (which encodes COT) can confer resistance of melanoma cells
8 }3 ~# d" | U1 q6 h# c: U/ Rto B-RAF inhibitors, whereas another paper found that melanomas can
' @+ w& }- q% r2 X$ Iacquire resistance due to mutations of N-RAS or increased expression 5 I, k: ~0 P& E8 r# \& \3 o, h
of PDGFRβ. Each of these resistance mechanisms seems to apply to at
+ d% i% O! k( q+ n; `0 qleast some patients on recent PLX4032 trial, whereas, surprisingly, so
& s* W/ k% @/ ?7 H c& Z! z* jfar no secondary B-RAF mutations have been observed.; x0 h, n. c2 _' Z5 u; P1 D
Ramin Nazarian et al.* @; B& x+ Z B
doi:10.1038/nature09626" Q. G4 S* S' C. J
Abstract: http://www.nature.com/nature/jou ... bs/nature09626.html
# U$ _; Y/ @& g" h V5 PArticle: http://www.nature.com/nature/jou ... ll/nature09626.html
* H1 h' w9 U2 q7 ? v; r+ m* J' ^/ |5 W0 A3 a4 [* r4 F! ?* V' a
Crystal structure of bacterial RNA polymerase bound with a
: U' O0 I; E m9 u' b) s* O4 }* stranscription inhibitor protein pp978 - 982( L4 g2 \: d: B* q: j3 D# I
A crystal structure of bacterial RNA polymerase (RNAP) bound to the
4 v2 x# R: l7 X" Gtranscription inhibitor Gfh1 reveals the mechanism of inhibition by
1 F7 _# x* l6 G7 ^# F9 l! C/ S, EGfh1 and an alternative ratcheted state of RNAP.
( D2 n& e( x6 n: J% c0 A3 ^Shunsuke Tagami et al.9 J7 q0 X& k1 h1 M
doi:10.1038/nature09573
% U) U. k( \4 |" A" p& d* GAbstract: http://www.nature.com/nature/jou ... bs/nature09573.html. `( h5 _' O4 b/ H1 j! u
Article: http://www.nature.com/nature/jou ... ll/nature09573.html
2 g) c. \0 m/ V/ m
7 C) J* ]9 P# S3 C& QSingle-molecule imaging reveals mechanisms of protein disruption by a
9 J- @; }( S4 J" [DNA translocase pp983 - 987
6 D: E* U5 a3 `0 ?$ M. fProtein machineries that move along the DNA, such as DNA polymerases & f* O# t; p) T4 q
and helicases, will necessarily encounter other bound proteins " v: |$ r5 h$ C
interacting with specific sites. Using 'curtains' of labelled DNA, ( ?# N C1 Y: k# B5 c+ y
this study measured whether such bound proteins interfere with the
) F3 F8 i2 @0 A) p4 I; ]% Zactivity of the bacterial DNA translocase RecBCD. The translocase is
) }& f: S( |) b# R; j+ g* Z- mable to push the proteins over nonspecific sites for thousands of base
3 @# }5 u2 O2 Z8 `- G5 \9 Z9 dpairs before they are displaced.
) b& u! `' ]. h/ [; e$ P. L- Z" {3 dIlya J. Finkelstein, Mari-Liis Visnapuu and Eric C. Greene: P1 D. q X q" g) e: P6 ^9 U
doi:10.1038/nature09561
6 C1 T& P* p+ H, L3 E; o0 AAbstract: http://www.nature.com/nature/jou ... bs/nature09561.html, [" A- k+ [( O( q5 d7 M
Article: http://www.nature.com/nature/jou ... ll/nature09561.html, V; p9 a. d, t# ?( E
1 H; Z2 t0 U; g% ?$ Y2 t9 Q
The mechanism of sodium and substrate release from the binding pocket
6 E& ~/ {. N1 g* ?of vSGLT pp988 - 991
- `# X7 p" \# W2 c8 sHere, a comprehensive study of the sodium/galactose transporter
- m1 A: B* L: b2 l! Z(vSGLT) is presented, consisting of molecular dynamics simulations, * M, ]6 ]% L [. U; y
biochemical characterization and a new crystal structure of the
^) x, L5 a$ v% z3 Y'inward-open' conformation. These experiments show that sodium exit 3 }2 h" R- A2 j
causes a reorientation of transmembrane helix 1, opening an inner gate $ G6 \4 |# h5 A; g) p0 ~
required for substrate exit, while also triggering minor rigid-body 9 u1 L! }5 x) C- Y8 L
movements in two sets of transmembrane helical bundles. This cascade
_7 a: s% B( O9 D! U& [9 C _) fof conformational changes is responsible for the proper timing of ion [7 X) } V- U- D
and substrate release. |
-
总评分: 威望 + 2
包包 + 5
查看全部评分
|
发表于 2010-12-16 16:18
非常好 谢谢楼主
发表于 2010-12-17 10:30
