The BRCT domain is a phospho-protein binding domain

The carboxyl-terminal domain (BRCT) of the Breast Cancer Gene 1 (BRCA1) protein is an evolutionarily conserved module that exists in a large number of proteins from prokaryotes to eukaryotes. Although most BRCT domain-containing proteins participate in DNA-damage checkpoint or DNA-repair pathways, or both, the function of the BRCT domain is not fully understood. We show that the BRCA1 BRCT domain directly interacts with phosphorylated BRCA1-Associated Carboxyl-terminal Helicase (BACH1). This specific interaction between BRCA1 and phosphorylated BACH1 is cell cycle regulated and is required for DNA damage-induced checkpoint control during the transition from G2 to M phase of the cell cycle. Further, we show that two other BRCT domains interact with their respective physiological partners in a phosphorylation-dependent manner. Thirteen additional BRCT domains also preferentially bind phospho-peptides rather than nonphosphorylated control peptides. These data imply that the BRCT domain is a phospho-protein binding domain involved in cell cycle control.     

汽蒸处理对落叶松木材化学性质的影响

本文研究了兴安落叶松(Larix gmelinii Rupr.)生材于常压下,汽蒸1、2、4、8、16、32、49、64、96h,试样化学成分的变化。结果表明:汽蒸是落叶松成材干燥工艺中十分有效的预处理工序,不仅能除去影响落叶松木材气体渗透性的树脂类物质,同时还能除去影响落叶松木材液体渗透性的水溶性物质,这种水溶性物质的主要成分是阿拉伯半乳聚糖。汽蒸过程中木材的酸度逐渐增加,同时材面颜色亦随之变深。汽蒸过程中综纤维素含量稍有下降,木素含量略有增大。试样中LCC价键断裂程度加深,少量降解程度大的低聚合度级份的半纤维素由材面溶出,其它级份的半纤维素亦有不同程度的水解降解。为了彻底除去树脂中的挥发性成分,汽蒸处理时间不应少于4h。     

The involvement of the anterior cingulate cortex in remote contextual fear memory

Although the molecular, cellular, and systems mechanisms required for initial memory processing have been intensively investigated, those underlying permanent memory storage remain elusive. We present neuroanatomical, pharmacological, and genetic results demonstrating that the anterior cingulate cortex plays a critical role in remote memory for contextual fear conditioning. Imaging of activity-dependent genes shows that the anterior cingulate is activated by remote memory and that this activation is impaired by a null alpha-CaMKII mutation that blocks remote memory. Accordingly, reversible inactivation of this structure in normal mice disrupts remote memory without affecting recent memory.     

Antarctic marine flora: uniquely devoid of kelps

The discovery of embryonic stages of the common large Antarctic brown seaweed Himantothallus has led to the conclusion that this plant, hitherto assigned equivocally to the Laminariales (kelps), is a member of the Desmarestiales. Moreover, field study of a large sample of Himantothallus and two other enigmatic brown algae, Phyllogigas and Phaeoglossum, has led to the merger of these three genera with the recognition of a single species, Himantothallus grandifolius. The correct placement of these kelp-like algae underscores the uniqueness of the Antarctic marine flora as the only cold-water flora without kelps.     

犬瘟热病毒融合蛋白融合区基因的序列分析

以分离的犬瘟热病毒（CDV）株感染Vero细胞后提取病毒RNA，经反转录后，用犬瘟热病毒的1对引物扩增出融合蛋白融合区的基因片断。经序列分析显示：分离株CDV－YZ－0101与CDV－YZ－0103在核苷酸和氨基酸水平上同源性一致，与CDV－YZ－0102、CDV－A75／17、CDV－ONPPDV2、PDV1在核苷酸和氮基酸水平上的同源性分别为99.6%、97.9%、92.9％、98.9%、76.2%、93.3%和98.9%、97.9%、98.9%、83.0%、97.9%，表明分离株和相关毒株的融合区基因存在差别。     

Amazon forests green-up during 2005 drought

Coupled climate-carbon cycle models suggest that Amazon forests are vulnerable to both long- and short-term droughts, but satellite observations showed a large-scale photosynthetic green-up in intact evergreen forests of the Amazon in response to a short, intense drought in 2005. These findings suggest that Amazon forests, although threatened by human-caused deforestation and fire and possibly by more severe long-term droughts, may be more resilient to climate changes than ecosystem models assume.