Upon S-Cdk activation, which protein is primarily recruited to the origin of replication?

Upon S-Cdk activation, which protein is primarily recruited to the origin of replication?

• A. Cdc6 is phosphorylated and recruited to the origin of replication
• B. DNA helicases are recruited to the origin of replication
• C. Primases are recruited to the origin of replication
• D. Cdc6 is dephosphorylated and recruited to the origin of replication

Answer: (C)

The correct response is that DNA helicases are recruited to the origin of replication upon S-Cdk activation. When S-Cdk is activated, it initiates various processes essential for DNA replication. One of these processes involves the recruitment of DNA helicases, which are crucial for unwinding the DNA double helix, allowing other proteins and enzymes access to the single-stranded DNA needed for replication. During the initiation phase of DNA replication, the activity of S-Cdk leads to the phosphorylation of proteins that regulate the replication process, including those that control helicase activity. This phosphorylation helps to coordinate the assembly of the replication machinery and ensures that the DNA strands are separated so that synthesis can occur. In contrast, the other options do not accurately describe the primary events initiated by S-Cdk activation. While Cdc6 is indeed involved in the recruitment of other proteins to the replication origin, it is typically not directly phosphorylated at this stage for recruitment, nor does its dephosphorylation directly relate to the action of S-Cdk. Primases, while important in the replication process, are not the primary proteins recruited at the onset of S-phase; they come into play after helicases have unwound the DNA. Therefore, the recruitment of DNA helicases

The correct response is that DNA helicases are recruited to the origin of replication upon S-Cdk activation. When S-Cdk is activated, it initiates various processes essential for DNA replication. One of these processes involves the recruitment of DNA helicases, which are crucial for unwinding the DNA double helix, allowing other proteins and enzymes access to the single-stranded DNA needed for replication.

During the initiation phase of DNA replication, the activity of S-Cdk leads to the phosphorylation of proteins that regulate the replication process, including those that control helicase activity. This phosphorylation helps to coordinate the assembly of the replication machinery and ensures that the DNA strands are separated so that synthesis can occur.

In contrast, the other options do not accurately describe the primary events initiated by S-Cdk activation. While Cdc6 is indeed involved in the recruitment of other proteins to the replication origin, it is typically not directly phosphorylated at this stage for recruitment, nor does its dephosphorylation directly relate to the action of S-Cdk. Primases, while important in the replication process, are not the primary proteins recruited at the onset of S-phase; they come into play after helicases have unwound the DNA. Therefore, the recruitment of DNA helicases