編譯|李言
Science, 6 Nov 2025, VOL 390, ISSUE 6773
《科學》2025年11月6日，第390卷，6773期
生物學Biology
Adipogenin promotes the development of lipid droplets by binding a dodecameric seipin complex
脂肪生成素通過結合十二聚體seipin復合物促進脂滴發育
▲ 作者：Chao Li, Xue-Nan Sun et al.
▲鏈接：
https://www.science.org/doi/10.1126/science.adr9755
▲ 摘要： 微蛋白脂肪生成素（Adig）主要在脂肪組織中表達。研究者發現Adig可與seipin相互作用形成穩定的剛性復合體。
研究者解析了分辨率為3.0埃的seipin-Adig復合體結構，發現哺乳動物seipin可組裝成兩種不同寡聚形態：十一聚體和十二聚體。Adig選擇性結合十二聚體形式，通過橋接并穩定相鄰亞基來增強seipin組裝。
功能上，該復合體在脂滴形成的早期和晚期階段均能促進其發育。在轉基因小鼠中，脂肪細胞特異性過表達Adig可增加脂肪量并擴大脂滴，而敲除Adig則會破壞棕色脂肪組織中的甘油三酯積累。因此，Adig可以通過與seipin的結構和功能相互作用來調節脂質儲存。
▲ Abstract： The microprotein adipogenin (Adig) is predominantly expressed in adipose tissues. Here, we found that Adig interacts with seipin to form a stable, rigid complex. We present the structure of the seipin-Adig complex at an overall resolution of ~3.0 angstroms. The structure revealed that mammalian seipin assembles into two distinct oligomeric forms: undecamers and dodecamers. Adig selectively bound to the dodecameric form and enhanced seipin assembly by bridging and stabilizing adjacent subunits. Functionally, this complex promoted lipid droplet development at both early and late stages. In transgenic mice, adipocyte-specific overexpression of Adig increased fat mass and enlarged lipid droplets, whereas Adig deletion disrupted triglyceride accumulation in brown adipose tissues. Thus, Adig can modulate lipid storage through its structural and functional interactions with seipin.
Direct targeting and regulation of RNA polymerase II by cell signaling kinases
細胞信號激酶對RNA聚合酶II的直接靶向與調控
▲ 作者：Preeti Dabas, Meritxell B. Cutrona et al.
▲鏈接：
https://www.science.org/doi/10.1126/science.ads7152
▲ 摘要： 在基因轉錄的不同階段，RNA聚合酶II（Pol II）羧基末端結構域（CTD）會被賦予不同的磷酸化標記。這些磷酸化CTD標記如同分子識別密碼，負責招募階段特異性的效應蛋白。
通過對約80%人類激酶組進行系統性篩選，研究者鑒定出117種能對CTD進行高位置選擇性磷酸化的激酶。這些激酶的共同特征在于它們能選擇性調控信號響應基因處的Pol II。
表皮生長因子受體（EGFR）作為細胞表面受體酪氨酸激酶，正是這種“直接作用于基因”的Pol II調控模式的典型例證。更廣泛而言，研究者的CTD激酶圖譜表明，Pol II是信號轉導激酶的直接調控終點——這些激酶不僅調控細胞生理活動，更與多種疾病的發生機制密切相關。
▲ Abstract： Distinct phosphorylation marks are placed on the carboxyl-terminal domain (CTD) of RNA polymerase II (Pol II) during different stages of gene transcription. These phospho-CTD marks function as a molecular recognition code for the recruitment of stage-specific effector proteins. Querying ~80% of the human kinome, we identified 117 kinases that phosphorylate the CTD with a high degree of positional selectivity. The unifying characteristic linking these diverse kinases is that they selectively regulate Pol II at signal-responsive genes. An example of such"direct-at-gene" Pol II regulation is displayed by epidermal growth factor receptor (EGFR), a cell surface receptor tyrosine kinase. More broadly, our atlas of CTD kinases implicates Pol II as a direct regulatory end point for signal-transducing kinases that govern cellular physiology and contribute to the etiology of numerous diseases.
材料科學Material Sciences
Strengthening Ni alloys with nanoscale interfaces of negative excess energy
利用負過剩能的納米尺度界面強化鎳合金
▲ 作者：J. X. Li, Z. H. Jin et al.
▲鏈接：
https://www.science.org/doi/10.1126/science.aea4299
▲摘要：納米晶與納米孿晶金屬的強度受限于其晶界或孿晶界在特征尺度（通常約10納米）以下的內在不穩定性。
通過實驗與密度泛函理論計算，研究者發現在過飽和Ni(Mo)固溶體中，具有負過剩能的面心立方—六方最密堆積相干界面比孿晶界更具穩定性。這種負過剩能界面可在Ni(Mo)固溶體中實現極高密度分布（平均間距約1納米），從而有效抑制塑性變形，使材料強度逼近理論極限。
實測結果表明，Ni(Mo)合金的楊氏模量隨界面密度顯著提升，最高達254.5吉帕，明顯高于同成分金屬玻璃與金屬間化合物（Ni3Mo）的模量值。
▲ Abstract： The strength of nanograined and nanotwinned metals is limited by the inherent instability of grain or twin boundaries below a length scale of typically about 10 nanometers. From experimental and density functional theory calculations, we found that the coherent interfaces between face-centered-cubic and hexagonal-close-packing lattices with a negative excess energy were more stable than twin boundaries in supersaturated Ni(Mo) solution. The negative excess-energy interface can be produced at extremely high density in Ni(Mo) solution with average spacing as small as about 1 nanometer, which inhibits plastic deformation and elevates the strength close to the theoretical value of the alloys. The measured Young’s modulus of the Ni(Mo) alloys increases obviously with the interface density, reaching 254.5 gigapascals, well above that of the same compositional metallic glass and intermetallic compound (Ni3Mo).
生態學Ecology
Extreme warming of Amazon waters in a changing climate
氣候變化背景下亞馬孫水域的極端升溫
▲ 作者：Ayan Santos Fleischmann, Fabrice Papa et al.
▲鏈接：
https://www.science.org/doi/10.1126/science.adr4029
▲摘要：2023年，一場前所未有的干旱與熱浪嚴重影響了亞馬孫水域，導致魚類和河豚大規模死亡。在監測的10個湖泊中，有5個出現異常高的白天水溫（超過37℃），其中一個大湖在整個約2米深的水體中溫度高達41℃，晝夜溫差達13℃。模型分析表明，強太陽輻射、水位下降、風速減弱及水體渾濁是造成高溫的主要驅動因素。
根據1990年至2023年該區域湖泊的衛星估算數據，這種極端升溫現象與長期存在的每十年0.6℃的升溫趨勢相吻合。隨著氣候持續變化，接近或超過水生生物耐熱極限的水溫狀況，在熱帶水域系統中很可能將變得更為普遍。
▲ Abstract： In 2023, an unprecedented drought and heat wave severely affected Amazon waters, leading to high mortality of fishes and river dolphins. Five of 10 lakes monitored had exceptionally high daytime water temperatures (over 37°C), with one large lake reaching up to 41°C in the entire approximately 2-meter-deep water column and up to 13°C of diel variation. Modeling showed that high solar radiation, reduced water depth and wind speed, and turbid waters were the main drivers of the high temperatures. This extreme heating of Amazon waters follows a long-term increase of 0.6°C/decade revealed by satellite estimates across the region’s lakes between 1990 and 2023. With ongoing climate change, temperatures that approach or exceed thermal tolerances for aquatic life are likely to become more common in tropical aquatic systems.
地球科學Earth Science
Shear-induced bubble nucleation in magmas
巖漿中的剪切誘導氣泡成核
▲ 作者：Olivier Roche, Jean-Michel Andanson et al.
▲鏈接：
https://www.science.org/doi/10.1126/science.adw8543
▲摘要：巖漿中氣泡的成核作用是控制火山噴發動力的關鍵因素。這項研究中，研究者聚焦于火山環境中普遍存在的、由黏性剪切作用觸發的揮發性飽和液體成核過程。
通過結合實驗室試驗、理論分析和數值模擬，研究者探究了在揮發性過飽和液體中，機械剪切能量促進氣體分子核形成與生長的條件。
研究結果表明，成核所需的臨界剪切應力隨揮發性過飽和度的增加而降低。對自然體系進行的量綱分析顯示，剪切誘變成核很可能發生在火山通道中，這一發現對巖漿脫氣過程和噴發模式具有重要啟示。
▲ Abstract： The nucleation of gas bubbles in magmas is fundamental to controlling the dynamics of volcanic eruptions. In this study, we addressed nucleation in a volatile-saturated liquid triggered by viscous shear, which is ubiquitous in volcanic environments. By combining laboratory experiments, theoretical analysis, and numerical simulations, we investigated the conditions under which the mechanical energy associated with shearing favors the formation and growth of gas molecule nuclei in a liquid supersaturated with volatiles. Our results reveal that the critical shear stress for nucleation decreases as the volatile supersaturation increases. Dimensional analysis applied to natural systems shows that shear-induced nucleation is likely to occur in volcanic conduits, which has implications for magma degassing processes and eruptive styles.
Cosmic dust reveals dynamic shifts in central Arctic sea-ice coverage over the past 30,000 years
宇宙塵埃揭示過去3萬年中北冰洋中部海冰覆蓋度的動態變遷
▲ 作者：Frank J. Pavia, Jesse R. Farmer et al.
▲鏈接：
https://www.science.org/doi/10.1126/science.adv5767
▲摘要：北冰洋海冰消融直接影響生物生產力、沿岸社區生計及地緣政治格局。要準確預測這些影響，需要從機制層面理解北極海冰對氣候變化的響應規律，但長期觀測記錄的匱乏始終是重要制約。
研究者通過測量釷-230和宇宙源氦-3兩種同位素，重建了北冰洋連續3萬年的海冰覆蓋變化史——這兩種同位素的埋藏比率會隨海冰覆蓋度發生規律性變化。研究者發現，末次盛冰期的北冰洋中部曾被永久性海冰覆蓋。
約1.5萬年前的冰消期開始出現海冰退縮，至溫暖的早全新世演變為季節性海冰覆蓋，隨后在晚全新世再度擴展。海冰變化與生物營養鹽消耗量呈現密切關聯，這支持了持續海冰消融將導致北冰洋中部出現營養鹽匱乏的科學預測。
▲ Abstract： Arctic sea-ice loss affects biological productivity, sustenance in coastal communities, and geopolitics. Forecasting these impacts requires mechanistic understanding of how Arctic sea ice responds to climate change, but this is limited by scarce long-term records. We present continuous 30,000-year reconstructions of sea-ice coverage from the Arctic Ocean based on measurements of two isotopes, thorium-230 and extraterrestrial helium-3, whose burial ratio changes with sea-ice coverage. We found that the central Arctic was perennially covered by sea ice during the last glaciation. Sea-ice cover retreated during the deglaciation approximately 15,000 years ago, culminating in seasonal sea-ice coverage in the warm early Holocene, before ice coverage increased into the late Holocene. Sea-ice changes closely correlate with biological nutrient consumption, supporting projections of a nutrient-starved central Arctic Ocean with continued sea-ice loss.
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