Thekey differencebetween p53 and p21is that p53 arrests the cell growth by holding thecell cycle at the G1/Sregulation point upon detectingDNA damage, while p21 binds to G1-S/CDK complexes upon induction by p53 and inhibits the activity of CDK complexes.
DNA repair is the process by which a cell collectively identifies and corrects the damage in DNA molecules. Many of these DNA damages structurally affect the DNA molecule. This can alter the cell’s ability to transcribe important genes, eventually leading to lethal diseases such as cancers. DNA damages often activate the p53-p21 pathway and cause G1 phase arrest in the cells. p53 and p21 are two importanttumor suppressor proteins.
CONTENTS
1.Overview and Key Difference
2.What is P53
3.What is P21
4.相似之处 - p53和p21
5.p53vs P21 in Tabular Form
6.Summary – P53 vs P21
What is P53?
p53is a tumor suppressor protein that arrests cell growth by holding the cell cycle at the G1/S regulation point upon detecting DNA damage. It is also the guardian of the genome. This homolog protein is crucial in multicellular vertebrates because it prevents cancer formation. In addition, P53 conserves the stability of the genome by preventing genome mutation. Hence, P53 is considered a tumor suppressor. This name was first suggested in 1979 based on the molecular mass of p53.
TheSDS-PAGE analysis表明p53是53千达顿(KDA)蛋白。此外,p53基因是人类癌症中最常见的突变基因。这表明p53在防止癌症形成中起着至关重要的作用。p53执行许多功能。它激活DNA修复蛋白,通过在G1/S调节点保持细胞周期来阻止细胞生长。它还引发凋亡,对于对短端粒的衰老反应至关重要。此外,在DNA损伤后通过p53诱导P21(抑制CDK4和CDK2活性)可以阻止G/S调节点的细胞周期。
What is P21?
p21是一种肿瘤抑制蛋白和一种CDK相互作用蛋白,在p53诱导后能够与G1-S/CDK复合物结合。一旦结合,它就会抑制CDK复合物的活性。它也被称为细胞周期蛋白依赖性激酶抑制剂。这是因为它能够抑制所有细胞周期蛋白/CDK复合物。p53诱导后,p21(CIPI/WAF1)结合并抑制细胞周期蛋白-CDK1,CDK2,CDK4/6复合物。因此,它充当DNA损伤期间G1/S相的细胞周期进程的调节剂。
此外,p21与增殖的细胞核抗原(PCNA)相互作用并抑制它。这样,p21在S期充当DNA合成的有效抑制剂。但是,它允许在S相中进行核苷酸切除修复。此外,据报道,该蛋白被CASP-3等胱天蛋白酶裂解,CASP-3会再次导致CDK2的戏剧性激活,从而抑制凋亡。
What are the Similarities Between P53 and P21?
- p53和p21是两个重要的肿瘤抑制蛋白。
- 两者都是小分子加权蛋白。
- These proteins are involved in the p53-p21 pathway.
- Both proteins are very important for the G1 phase arrest of the cell cycle during DNA damage.
- 两种蛋白质都能够预防癌症形成。
是什么Difference Between P53 and P21?
p53is a tumor suppressor protein that arrests the cell growth by holding the cell cycle at the G1/S regulation point upon detecting DNA damage, while p21 is a tumor suppressor protein and a CDK interacting protein that is capable of binding to G1-S/CDK complexes and inhibiting the activity of CDK complexes upon induction by p53. So, this is the key difference between p53 and p21. Furthermore, P53 initiates apoptosis if the DNA damages are irreparable but, p21 inhibits apoptosis due to cleavage by caspases.
The below infographic lists the differences between p53 and p21 in tabular form for side by side comparison.
Summary – P53 vs P21
DNA damages often activate the p53-p21 pathway and cause G1 phase arrest of the cell cycle. This process is very important for controlling cancer formation. P53 and p21 are two important tumor suppressor proteins in this pathway. P53 is a protein that arrests the cell growth by holding the cell cycle at the G1/S regulation point upon detecting DNA damage, while p21 is a protein that is capable of binding to G1-S/CDK complexes upon induction by p53 and inhibiting the activity of CDK complexes. Thus, this is the summary of the difference between p53 and p21.
Reference:
1. “p53.” An Overview | ScienceDirect Topics.
2. “P21.” An Overview | ScienceDirect Topics.
Image Courtesy:
1. “031-P53-1olg 1tup 1ycq” ByProtein Data Bank. David Goodsell. –(CC BY 3.0)via Commons Wikimedia
2. “ATM target proteins (new)”在英语Wikipedia上通过蜂窝生物化学II(CC BY-SA 3.0)via Commons Wikimedia
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