Western blot analysis of Phospho-Cdk2 (Y15) expressed in 293T,HeLa using Phospho-Cdk2 (Y15) Rabbit mAb at 1:1000. Secondary antibody: HRP Goat Anti-Rabbit IgG (H+L) at 1:5000. Lysates/proteins: 30ug per lane. Blocking buffer: 5% non-fat dry milk in TBST. Detection: ECL Enhanced Kit. Exposure time: 120s.
Immunohistochemistry - Phospho-Cdk2 (Y15) Rabbit mAb
Immunohistochemical analysis of paraffin-embedded human bladder cancer, using Phospho-CDK2 (Y15) Antibody.
Western blot analysis of Phospho-Cdk2 (Y15) expressed in 293T,HeLa using Phospho-Cdk2 (Y15) Rabbit mAb at 1:1000. Secondary antibody: HRP Goat Anti-Rabbit IgG (H+L) at 1:5000. Lysates/proteins: 30ug per lane. Blocking buffer: 5% non-fat dry milk in TBST. Detection: ECL Enhanced Kit. Exposure time: 120s.
Immunohistochemistry - Phospho-Cdk2 (Y15) Rabbit mAb
Immunohistochemical analysis of paraffin-embedded human bladder cancer, using Phospho-CDK2 (Y15) Antibody.
This gene encodes a member of a family of serine/threonine protein kinases that participate in cell cycle regulation. The encoded protein is the catalytic subunit of the cyclin-dependent protein kinase complex, which regulates progression through the cell cycle. Activity of this protein is especially critical during the G1 to S phase transition. This protein associates with and regulated by other subunits of the complex including cyclin A or E, CDK inhibitor p21Cip1 (CDKN1A), and p27Kip1 (CDKN1B). Alternative splicing results in multiple transcript variants.
基因ID
1017
基因名
CDK2
Swiss
P24941
别名
CDK2;CDKN2;p33(CDK2)
功能
Serine/threonine-protein kinase involved in the control of the cell cycle; essential for meiosis, but dispensable for mitosis. Phosphorylates CTNNB1, USP37, p53/TP53, NPM1, CDK7, RB1, BRCA2, MYC, NPAT, EZH2. Triggers duplication of centrosomes and DNA. Acts at the G1-S transition to promote the E2F transcriptional program and the initiation of DNA synthesis, and modulates G2 progression; controls the timing of entry into mitosis/meiosis by controlling the subsequent activation of cyclin B/CDK1 by phosphorylation, and coordinates the activation of cyclin B/CDK1 at the centrosome and in the nucleus. Crucial role in orchestrating a fine balance between cellular proliferation, cell death, and DNA repair in human embryonic stem cells (hESCs). Activity of CDK2 is maximal during S phase and G2; activated by interaction with cyclin E during the early stages of DNA synthesis to permit G1-S transition, and subsequently activated by cyclin A2 (cyclin A1 in germ cells) during the late stages of DNA replication to drive the transition from S phase to mitosis, the G2 phase. EZH2 phosphorylation promotes H3K27me3 maintenance and epigenetic gene silencing. Phosphorylates CABLES1 (By similarity). Cyclin E/CDK2 prevents oxidative stress-mediated Ras-induced senescence by phosphorylating MYC. Involved in G1-S phase DNA damage checkpoint that prevents cells with damaged DNA from initiating mitosis; regulates homologous recombination-dependent repair by phosphorylating BRCA2, this phosphorylation is low in S phase when recombination is active, but increases as cells progress towards mitosis. In response to DNA damage, double-strand break repair by homologous recombination a reduction of CDK2-mediated BRCA2 phosphorylation. Phosphorylation of RB1 disturbs its interaction with E2F1. NPM1 phosphorylation by cyclin E/CDK2 promotes its dissociates from unduplicated centrosomes, thus initiating centrosome duplication. Cyclin E/CDK2-mediated phosphorylation of NPAT at G1-S transition and until prophase stimulates the NPAT-mediated activation of histone gene transcription during S phase. Required for vitamin D-mediated growth inhibition by being itself inactivated. Involved in the nitric oxide- (NO) mediated signaling in a nitrosylation/activation-dependent manner. USP37 is activated by phosphorylation and thus triggers G1-S transition. CTNNB1 phosphorylation regulates insulin internalization. Phosphorylates FOXP3 and negatively regulates its transcriptional activity and protein stability (By similarity). Phosphorylates CDK2AP2 (PubMed:12944431).
a. 贴壁培养细胞收集
去除贴壁细胞的培养液，用PBS、NS或无血清培养基清洗1次，低速离心，弃上清，留取沉淀。
b. 悬浮培养细胞收集
速离心悬浮细胞，弃上清，收集沉淀。手指轻弹细胞，使其松散。
c. 组织样本收集
把组织剪切成细小的碎片，越小越好。取液氮或超低温冰箱中冷冻30min以上的组织，迅速用液氮研磨，研磨过程尽量控制在1~2min之内，以减少蛋白的降解。
（2）总蛋白提取
a. 细胞/组织裂解
将装有细胞沉淀或组织碎片的容器完全插入冰中。细胞沉淀按照1mL裂解液/107个细胞(1个T75培养瓶细胞量)的比例加入相应体积的裂解液（细胞量足够时都加入3mL，不足时根据细胞量计算），裂解20min，每隔5min将离心管置于涡旋振荡仪上震荡10s。组织碎片按照0.5mL 裂解液/100mg组织向匀浆器中加入蛋白裂解液，每3min研磨一次，重复5次，使组织尽量碾碎。（裂解液中根据需要选择添加或不添加蛋白酶抑制剂）。
b. 离心
把裂解好的样品配平后，置于预冷的高速冷冻离心机中，12000 rpm，15min。
c. 蛋白变性
完成离心后，上清即为蛋白提取液。吸取少量蛋白提取液做蛋白浓度测定。向剩余的蛋白提取液的离心管中加入1/5上清体积的5×Loading Buffer（最终工作液为1X），待干式恒温器温度升至95℃后，将1.5mL离心管插入加热孔中，95℃加热变性10min，待液体完全冷却后置于-20℃保存。
（3）蛋白浓度测定（BCA法）
a. BCA工作液的配置
根据样品数量，按50体积BCA试剂A加入1体积BCA试剂B（50:1）配置适量BCA工作液，充分混匀。BCA工作液室温24h内稳定。
b. 标准品测定
取10μl蛋白标准品（5mg/ml BSA）稀释至50μl，使终浓度为1mg/ml。稀释后的蛋白标准品可以-20℃长期保存。此标准品溶液的稀释液可使用去离子水或1*PBS。将标准品按0、1、2、4、8、12、16、20μl加入到96孔板中，加稀释液补足到20μl（见附表）。加适当体积样品到96孔板的样品孔中，如果样本不足20μl，需加稀释液补足到20μl。请注意记录样品体积。各孔加入200μl BCA工作液，37℃放置20-30min。用酶标仪测定A562，或540-595nm之间的其他波长吸光度。根据标准曲线和使用的样品体积计算出样品的蛋白浓度。
a. Western Transfer Buffer至少提前2h （即开始电泳后）放入-20℃冰箱预冷，但注意避免结冰。
b. 根据胶体大小,将Filter Paper及Nitrocellulose membrane剪裁至合适尺寸。
c. 目的蛋白＞20KD选择0.45μm NC膜/PVDF膜；目的蛋白＜20KD选择0.2μmNC膜或PVDF膜，选择完毕后将NC膜放在Western Transfer Buffer中浸泡备用，注意如使用的是PVDF膜需先放入甲醇中浸泡5-10min，再放入Western Transfer Buffer中浸泡备用。
（2）裂解液&洗杂液：Cell lysis buffer for IP (without inhibitors)
（3）蛋白酶抑制剂
（4）封闭液：含 3% BSA 的 1X PBS
（5）1×PBS 缓冲液
（6）5×loding buffer（使用时用去离子水稀释至工作浓度即可）
（7）Control IgG （AC005/ AC011/AC034）
二、实验步骤
1、样本处理
（1）贴壁培养细胞
a. 取裂解液室温溶解混匀，根据需要选择添加或不添加蛋白酶抑制剂。
b. 去除贴壁细胞的培养液，用PBS、NS或无血清培养基清洗1次，低速离心，弃上清，留取沉淀。
c. 按照6孔板每孔加入100~200μl裂解液的比例，加入裂解液。移液器轻轻吹打，使裂解液和细胞充分接触。通常裂解液作用于细胞1~5s内，细胞会被裂解。
d. 1000~12000g，离心3~5min（如果用冷冻离心机4℃效果更佳），取上清。
（2）悬浮培养细胞
a. 取裂解液室温溶解混匀，根据需要选择添加或不添加蛋白酶抑制剂。
b. 速离心悬浮细胞，弃上清，收集沉淀。
c. 手指轻弹细胞，使其松散。按照6孔板每孔加入100~200μl裂解液的比例，加入NP-40裂解液。通常6孔板每孔加入100~200μl裂解液已经足够，但如果细胞密度非常高可以适当加大裂解液的用量150~200μl，再用手指轻弹以充分裂解细胞。充分裂解后应无明显沉淀。
d. 1000~12000g，离心3~5min（如果用冷冻离心机4℃效果更佳），取上清。
（3）组织样本
a. 取裂解液室温溶解混匀，根据需要选择添加或不添加蛋白酶抑制剂。
b. 把组织剪切成细小的碎片，越小越好。
c. 取液氮或超低温冰箱中冷冻30min以上的组织，迅速用液氮研磨，研磨过程尽量控制在1~2min之内，以减少蛋白的降解。
d. 按照每20mg组织加入100~200μl裂解液的比例，加入含有PMSF的裂解液。冰上或4℃裂解30-60min。（步骤3、4也可采用以下过程：按照每20mg组织加入100~200μl裂解液的比例加入NP-40裂解液。用玻璃匀浆器或组织研磨器匀浆，直至充分裂解，过程尽量控制在1~2min之内，以减少蛋白的降解。）
e. 按照每20mg组织加入100~200μl裂解液的比例，加入裂解液。
f. 1000~12000g，4℃离心10~15min（如无低温离心机，室温下离心也可），取上清。
2、磁珠预处理
（1）将rProtein A/G Plus MaqPoly Beads颠倒或漩涡混匀，翻转瓶身发现底部无黑色沉淀即可。
（2）取30μl rProtein A/G Plus MaqPoly Beads至新的EP管中，放在磁分离器上，待溶液澄清后，用移液器吸弃保护液。
（3）将EP管从磁分离器上取下来，加入1ml Cell lysis buffer for IP (without inhibitors)，混匀，放置在磁分离器上，收集磁珠，用移液器吸弃洗杂液，重复2次。
