That CtIP levels are co-dependent o

That CtIP levels are co-dependent on Mre11 and CDK2 suggests a func¬tional relationship may exist among these factors. Hence, we conducted a series of coimmunoprecipitation experiments to explore the possi¬bility that MRN and CDK2 function together in a multiprotein com¬plex. First, endogenous Mre11 was immunoprecipitated from MEFs, and both CDK2 and cyclin A were observed to coimmunoprecipitate (Fig. 3a). To address the specificity of the coimmunoprecipitations and potential complexes, we blotted for cyclin D1, which is present in G1 and not known to associate with CDK2. Cyclin D1 was not detected in the coimmunoprecipitate fractions (Fig. 3a). Conversely, upon pre¬cipitation of hemagglutinin (HA)-tagged CDK2 transiently expressed in human cells (HeLa), we detected Mre11, Rad50 and NBS1 (Fig. 3b). In addition, when cyclin A was precipitated, Mre11 was present in the coimmunoprecipitation eluate (Fig. 3c). Finally, in cells deficient for MRN (Mre11−/−), CDK2 maintained association with cyclin A (Fig. 3c). Together, these findings indicate that MRN associates in vivo with CDK2 and its S-phase binding partner cyclin A.
Next, endogenous Mre11 was immunoprecipitated from CDK2−/− MEFs to determine whether other CDK family members associate with Mre11. Whereas NBS1 was detected in the coimmunoprecipitation fraction, no CDKs were identified by western blot analysis with an antibody to the highly conserved cyclin binding PSTAIR helix (Fig. 3d). In addition, cyclin A was not detected. Thus, our coimmunoprecipitations appear to be quite specific, and they support the notion that MRN does not associate globally with CDK–cyclins. We interpret the minimal impact on CtIP levels in
CDK2−/− cells (Fig. 2d) to indicate that an alternative kinase acts without Mre11 interaction. However, we cannot rule out the pos¬sibility that either weak interaction occurs below our detection limit or an uncharacterized kinase interacts that is not recognized by the PSTAIRE antibody interacts with Mre11.

結果 (繁體中文) 1:

That CtIP levels are co-dependent on Mre11 and CDK2 suggests a func¬tional relationship may exist among these factors. Hence, we conducted a series of coimmunoprecipitation experiments to explore the possi¬bility that MRN and CDK2 function together in a multiprotein com¬plex. First, endogenous Mre11 was immunoprecipitated from MEFs, and both CDK2 and cyclin A were observed to coimmunoprecipitate (Fig. 3a). To address the specificity of the coimmunoprecipitations and potential complexes, we blotted for cyclin D1, which is present in G1 and not known to associate with CDK2. Cyclin D1 was not detected in the coimmunoprecipitate fractions (Fig. 3a). Conversely, upon pre¬cipitation of hemagglutinin (HA)-tagged CDK2 transiently expressed in human cells (HeLa), we detected Mre11, Rad50 and NBS1 (Fig. 3b). In addition, when cyclin A was precipitated, Mre11 was present in the coimmunoprecipitation eluate (Fig. 3c). Finally, in cells deficient for MRN (Mre11−/−), CDK2 maintained association with cyclin A (Fig. 3c). Together, these findings indicate that MRN associates in vivo with CDK2 and its S-phase binding partner cyclin A.接下來，內源性 Mre11 是從 CDK2−/− 小鼠，以確定是否其他 CDK 家族成員將與 Mre11 相關聯的修剪。而在 coimmunoprecipitation 分數中檢測到 NBS1，沒有激酶經印跡分析與抗體的高度保守的細胞週期蛋白綁定 PSTAIR 螺旋 (圖 3d)。此外，細胞週期蛋白 A 未檢測到。因此，我們的 coimmunoprecipitations 似乎是很特別的和他們支援 MRN 無法不與 CDK — — 細胞週期蛋白全球聯繫的概念。我們解釋對 CtIP 水準的影響最小CDK2−/− 細胞 (圖 2d)，以指示替代激酶行為無需 Mre11 交互。然而，我們不能排除出 pos¬sibility，弱相互作用發生下面我們檢出限或蛋白的激酶交互程式不能識別的 PSTAIRE 抗體與 Mre11 進行交互。

結果 (繁體中文) 2:

該CtIP水平共同依賴MRE11和CDK2建議一個func¬tional關係可能這些因素之間存在。因此，我們進行了一系列的免疫共沉澱實驗探索possi¬bility的MRN和CDK2功能一起在一個多蛋白com¬plex。第一，內源性MRE11從MEF中免疫沉澱，並且兩個CDK2和細胞週期蛋白A，觀察到免疫共沉澱（圖3a）。為了解決coimmunoprecipitations和潛在複合物的特異性，我們印跡對細胞週期蛋白D1，這是目前在G1和不已知與CDK2關聯。週期蛋白D1未在免疫共沉澱的級分（圖3a）來檢測。相反地，當對血凝素（HA）-tagged CDK2瞬時表達在人細胞（HeLa細胞）pre¬cipitation，我們檢測到MRE11，Rad50的和NBS1（圖3b）。此外，當細胞週期蛋白A沉澱，MRE11存在於免疫共沉澱洗脫液（圖3c）。最後，在細胞缺陷的MRN（MRE11 - / - ），CDK2保持與細胞週期蛋白A（圖3c中）關聯。總之，這些發現表明，MRN同夥體內與CDK2和其S相結合伴侶細胞週期蛋白A.
接著，內源性MRE11從CDK2免疫沉澱- / -的MEF，以確定是否有其他的CDK家族成員關聯與MRE11。而NBS1在免疫共沉澱級分中檢測到，沒有激酶被鑑定通過Western印跡分析與抗體的高度保守的細胞週期蛋白結合PSTAIR螺旋（圖3d）。此外，細胞週期蛋白A沒有檢測。因此，我們的coimmunoprecipitations似乎是非常具體的，他們支持MRN並不與全球CDK-細胞週期相關聯的概念。我們解釋上CtIP水平的影響最小
CDK2 - / -細胞（圖2D），以指示不MRE11相互作用的替代激酶的行為。但是，我們不能排除，要么弱相互作用發生低於我們的檢測限的未鑑定的激酶進行交互，而並非由該PSTAIRE抗體識別與MRE11交互的pos¬sibility。

結果 (繁體中文) 3:

水准有限，資訊平臺依賴Mre11和CDK2的提示功能¬關係之間可能存在的這些因素。囙此，我們進行了一系列的免疫共沉澱實驗探索的可能性，¬MRN和CDK2功能結合在一起的一個多¬叢COM。首先，進行免疫沉澱細胞內源性MRE11，和觀察coimmunoprecipitate兩CDK2和cyclin（圖3A）。為了解决潜在的免疫共沉澱科技和複合物的特异性，我們在對細胞週期蛋白D1，這是現時在G1和沒有已知的與CDK2。Cyclin D1是不是在coimmunoprecipitate檢出組分（圖3A）。相反，在前¬血凝素（HA）降水在CDK2在人類細胞中暫態表達（Hela），我們發現Mre11，Rad50 NBS1（圖3b）。此外，當細胞沉澱，MRE11在免疫共沉澱洗脫現時（圖3C）。最後，在細胞缺陷的MRN（MRE11−/−），CDK2保持與cyclin A協會（圖3C）。一起，這些結果表明，MRN聯營與CDK2和S相結合的伴侶cyclin A
下體內內源性MRE11是沉澱CDK2−/−MEFs確定其他CDK家族成員與Mre11。而在免疫共沉澱檢測NBS1是分數，沒有CDK通過用抗體的免疫印迹分析確定的高度保守的細胞週期蛋白結合PSTAIR螺旋（圖3d）。此外，未檢測到細胞週期蛋白。囙此，我們的免疫共沉澱科技似乎是非常具體的，他們支持這一概念，MRN沒有關聯的全球–細胞CDK。我們認為在
CDK2−/−細胞CtIP水准影響最小（圖2D）表明另一種激酶相互作用行為沒有發生。然而，我們不能排除的可能性，無論是POS¬弱相互作用發生在我們的檢測限或非激酶作用不是由PSTAIRE抗體識別與
MRE11。