cell septum assembly

Definition

Target type: biologicalprocess

The assembly and arrangement of a cellular component that is composed of peptidoglycan and often chitin in addition to other materials and usually forms perpendicular to the long axis of a cell or hypha. It grows centripetally from the cell wall to the center of the cell and often functions in the compartmentalization of a cell into two daughter cells. [GOC:mtg_cell_cycle]

Cell septum assembly is a fundamental process in bacterial cell division. It involves the formation of a new cell wall that separates the two daughter cells. This process is highly regulated and involves a complex interplay of proteins and enzymes. Here's a detailed description of the biological process:

**1. Initiation:**

* **Z-ring formation:** The process begins with the formation of a ring-like structure called the Z-ring, composed of the protein FtsZ. This ring forms at the midpoint of the cell, marking the future site of septum formation.
* **Recruitment of other proteins:** The Z-ring serves as a platform for the recruitment of other proteins essential for septum assembly, including FtsA, ZipA, and FtsK. These proteins play crucial roles in stabilizing the Z-ring and anchoring it to the cell membrane.

**2. Septum Assembly:**

* **Peptidoglycan synthesis:** Once the Z-ring is established, the synthesis of new peptidoglycan, the major component of bacterial cell walls, begins. This process is carried out by a complex machinery called the divisome, which includes enzymes like penicillin-binding proteins (PBPs).
* **Inward growth:** New peptidoglycan is synthesized on the inside of the existing cell wall, causing the septum to grow inward, constricting the cell. This constriction is driven by the polymerization of FtsZ and the activity of other proteins involved in cell wall synthesis.
* **Membrane invagination:** As the septum grows inward, the cell membrane also invaginates, forming a central constriction that separates the two daughter cells.

**3. Completion and Separation:**

* **Completion of the septum:** The septum continues to grow until it completely separates the two daughter cells. This process involves the coordinated activity of multiple proteins, including PBPs, FtsK, and others.
* **Daughter cell separation:** Once the septum is complete, the two daughter cells separate, marking the end of the division cycle. This separation is facilitated by the breakdown of the peptidoglycan at the septum, which is mediated by autolysins.

**4. Regulation:**

* **Spatial and temporal control:** The formation of the septum is tightly regulated to ensure accurate and timely division. This regulation is achieved by a complex interplay of signaling pathways and regulatory proteins that control the activity of the divisome.
* **Environmental cues:** The process of cell septum assembly can be influenced by environmental factors, such as nutrient availability, cell density, and stress.

**In summary,** cell septum assembly is a tightly regulated and complex process that involves the coordinated activity of multiple proteins and enzymes. It is crucial for bacterial cell division and is essential for the survival and propagation of bacteria.
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Proteins (1)

Compounds (5)