The swface-enhanced Raman spectra (SERS) of dopamine, norepinephrlne, epinephrine, eplnlne, isoproterenol, 3meth-oxytyramlne, and oatechd In pH 7.2 buffers on a silver ektrod@ are reported. Catechol and the c a t -are shown to be COordlMted to diver through both oxygens. The methoxylated derlvatlve Is a monodentate complex. Intenskies maximize near -0.9 V vs saturated calomel electrode. The strongest bands In the spwtra are phendic carbon-oxygen stretches and the vlOb modes around 1270 and 1480 cm-l, respectively. Ascorbate, acetylchdlne, glutathione, L-Dopa, and the catecholamine acetlc acid metabolites are SERShracHveunderthemeasuementcondltknr. Dopamkre detectlon lM for the vl Ob band Is 3 X lo-' Y wlth a 10-s measurement tlme.

RAP80 localizes to sites of DNA insults to enhance the DNA-damage responses. Here we identify TRAIP/RNF206 as a novel RAP80-interacting protein and find that TRAIP is necessary for translocation of RAP80 to DNA lesions. Depletion of TRAIP results in impaired accumulation of RAP80 and functional downstream partners, including BRCA1, at DNA lesions. Conversely, accumulation of TRAIP is normal in RAP80-depleted cells, implying that TRAIP acts upstream of RAP80 recruitment to DNA lesions. TRAIP localizes to sites of DNA damage and cells lacking TRAIP exhibit classical DNA-damage response-defect phenotypes. Biochemical analysis reveals that the N terminus of TRAIP is crucial for RAP80 interaction, while the C terminus of TRAIP is required for TRAIP localization to sites of DNA damage through a direct interaction with RNF20–RNF40. Taken together, our findings demonstrate that the novel RAP80-binding partner TRAIP regulates recruitment of the damage signalling machinery and promotes homologous recombination.

Sustaining genomic integrity is essential for preventing onset of cancers. Therefore, human cells evolve to have refined biological pathways to defend genetic materials from various genomic insults. DNA damage response and DNA repair pathways essential for genome maintenance are accomplished by cooperative executions of multiple factors including breast cancer type 1 susceptibility protein (BRCA1). BRCA1 is initially identified as an altered gene in the hereditary breast cancer patients. Since then, tremendous efforts to understand the functions of BRAC1 reveal that BRCA1 is found in distinct complexes, including BRCA1-A, BRCA1-B, BRCA1-C, and the BRCA1/ PALB2/BRCA2 complex, and plays diverse roles in a context-dependent manner. Among the complexes, BRCA1-A is critical for BRCA1 recruitment to the sites of DNA damage. Factors comprising the BRCA1-A include RAP80, CCDC98/Abraxas, BRCC36, BRCC45, BARD1, BRCA1, and MERIT40, a RAP80-associated factor. In this review, we summarize recent findings of the factors that form the BRCA1-A complex.

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Background: RAP80, a component of the BRCA1-A complex, is crucial in the cell cycle checkpoint and DNA damage repair. Results: RAP80 phosphorylation by Cdk1 is important for sensitivity to ionizing radiation and G 2 /M checkpoint control. Conclusion: Cdk1-mediated RAP80 phosphorylation is important for the DNA damage response. Significance: The findings provide new implications for the interplay of the DNA damage signaling pathway and RAP80 phosphorylation.

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NLBP (novel LZAP-binding protein) was recently shown to function as a tumor suppressor capable of inhibiting the NFκB signaling pathway. NLBP is also known as a negative regulator of cell invasion, and its expression is reduced in several cancer cell lines that have little invasive activity. Although these phenomena suggest that NLBP may be a potential tumor suppressor, its role as a tumor suppressor in human lung cancer is not well established. In contrast to our expectation, NLBP was highly expressed in the early stage of lung adenocarcinoma tissues, and overexpression of NLBP promoted proliferation of H1299 lung adenocarcinoma cells. We also found that p120 catenin (p120ctn) was a novel binding partner of NLBP, and that NLBP binds to the regulatory domain of p120ctn, and p120ctn associates with N-terminal region of NLBP, respectively. This binding leads to p120ctn stability to inhibit proteasomal degradation of p120ctn by inhibiting its ubiqutination. In addition, we also found that overexpression of NLBP and p120ctn in human lung cancer are closely related with adenocarcinoma compared with squamous cell carcinoma. Taken together, our findings reveal that NLBP is highly overexpressed in human lung adenocarcinoma, and that overexpression of NLBP promotes the cell proliferation of lung adenocarcinoma through interacting with p120ctn and suggest that NLBP may function as an oncogene in early stage carcinogenesis of lung adenocarcinoma.

The error-free segregation of chromosomes, which requires the precisely timed search and capture of chromosomes by spindles during early mitotic and meiotic cell division, is responsible for genomic stability and is achieved by the spindle assembly checkpoint in the metaphase-anaphase transition. Mitotic kinases orchestrate M phase events, such as the reorganization of cell architecture and kinetochore (KT) composition with the exquisite phosphorylation of mitotic regulators, to ensure timely and temporal progression. However, the molecular mechanisms underlying the changes of KT composition for stable spindle attachment during mitosis are poorly understood. Here, we show that the sequential action of the kinase Cdk1 and the phosphatase Cdc14A control spindle attachment to KTs. During prophase, the mitotic spindle protein Spag5/Astrin is transported into centrosomes by Kinastrin and phosphorylated at Ser-135 and Ser-249 by Cdk1, which, in prometaphase, is loaded onto the spindle and targeted to KTs. We also demonstrate that Cdc14A dephosphorylates Astrin, and therefore the overexpression of Cdc14A sequesters Astrin in the centrosome and results in aberrant chromosome alignment. Mechanistically, Plk1 acts as an upstream kinase for Astrin phosphorylation by Cdk1 and targeting phospho-Astrin to KTs, leading to the recruitment of outer KT components, such as Cenp-E, and the stable attachment of spindles to KTs. These comprehensive findings reveal a regulatory circuit for protein targeting to KTs that controls the KT composition change of stable spindle attachment and chromosome integrity.The maintenance of genome integrity during mitosis is crucial for cell survival and organismal development. To generate two daughter cells with identical genetic information, each sister chromatid must be captured by spindle microtubules (MTs), 4 aligned at the mitotic equator, and segregated toward the spindle poles. Cells build a proteinaceous structure, known as the KT, at the centromere and form a bipolar spindle with an amphitelic spindle attachment to achieve accurate chromosome segregation (1). The KT is made up of protein complexes that control its localization on the chromosome, assembly, attachment to spindle MTs, and chromosome movements, such as congression and segregation (2). KTs lacking essential proteins for KT-MT attachment, such as Knl1, Mis12, and Ndc80 protein subcomplexes, are unable to attach to spindle MTs (3), which in turn results in chromosome loss and concurrent cell death (4).Entry into mitosis is controlled by the concerted action of several mitotic kinases, such as Cyclin-dependent kinase 1 (Cdk1), Polo-like kinase 1 (Plk1), and Aurora A, whose activities are regulated indirectly in a positive feedback loop (5). Plk1 activates Cdk1 by phosphorylating and activating Cdc25, which then removes inhibitory phosphorylation at the Thr-14 and Tyr-15 sites of Cdk1. Aurora A phosphorylates Thr-210 in the active loop of Plk1 with the aid of Bora (6). Cdk1 also activates Plk1 via Bora phosphorylation to promote mit...