positive regulation of lateral attachment of mitotic spindle microtubules to kinetochore

Definition

Target type: biologicalprocess

Any process that activates or increases the frequency, rate or extent of lateral attachment of mitotic spindle microtubules to kinetochore. [GO_REF:0000058, GOC:TermGenie, PMID:22375062]

Positive regulation of lateral attachment of mitotic spindle microtubules to kinetochore involves a complex interplay of molecular events that ensure accurate chromosome segregation during cell division. The process is tightly regulated and involves multiple proteins that interact with microtubules, kinetochores, and other cellular components.

**Key players and their roles:**

1. **Kinetochore:** A protein complex assembled on the centromere of each chromosome. It serves as the attachment site for microtubules.
2. **Microtubules:** Long, hollow filaments that form the mitotic spindle. They are responsible for segregating chromosomes during cell division.
3. **Motor proteins:** These proteins, such as dynein and kinesin, are responsible for moving microtubules and chromosomes.
4. **Regulatory proteins:** These proteins, including Aurora B kinase and the spindle checkpoint proteins, control the timing and accuracy of attachment.

**Steps in the process:**

1. **Initial attachment:** Microtubules from the spindle poles encounter the kinetochore and initiate a weak attachment. This initial interaction is often unstable and transient.
2. **Lateral attachment:** The initial attachment triggers a cascade of events that lead to the formation of stable, lateral attachments. This process involves the recruitment of specific proteins to the kinetochore-microtubule interface.
3. **Stabilization and correction:** The lateral attachment is further stabilized by the removal of unstable attachments and the recruitment of additional proteins. Aurora B kinase plays a key role in this step by phosphorylating proteins involved in unstable attachment.
4. **Congression:** Once a stable lateral attachment is established, the chromosomes are pulled towards the center of the cell by microtubule depolymerization and motor protein activity.
5. **Tension:** The final stage of attachment involves the generation of tension on the kinetochore-microtubule interface. This tension ensures that chromosomes are correctly aligned on the metaphase plate and that the chromosomes are correctly segregated during anaphase.

**Regulation of the process:**

The process of lateral attachment is tightly regulated to ensure accurate chromosome segregation. The spindle checkpoint ensures that all chromosomes are properly attached before the cell enters anaphase. This checkpoint is activated by unattached or incorrectly attached kinetochores.

**Consequences of errors:**

Errors in the process of lateral attachment can lead to aneuploidy, a condition where cells have an abnormal number of chromosomes. Aneuploidy can contribute to various diseases, including cancer.

In summary, positive regulation of lateral attachment of mitotic spindle microtubules to kinetochore is a complex process that involves multiple proteins and signaling pathways. This process is critical for ensuring accurate chromosome segregation during cell division.'
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Proteins (1)

Compounds (312)