Name: microtubules guide cellulose alignment
Uploaded: 2023-04-30T11:56:49.000Z
Duration: 1 min 2 s
Channel: JoVE

During plant cell division, the thin cell plate formed during cytokinesis is restructured into the cell walls of daughter cells.
As the young cell grows, more and more cellulose is added to the cell wall.
Cellulose synthase&#160;or CESA is a multimeric enzyme that uses cytosolic UDP-glucose to spin out cellulose chains on the ECM face of the plasma membrane.
CESA moves on microtubule-defined channels just under the plasma membrane, to orient the newly deposited cellulose chains.
The nascent cellulose chains self-assemble to form microfibrils.
The distal ends of the stiff microfibrils integrate into the cell wall while the elongating proximal ends push CESA along microtubule tracks.
As the cell expands, the microtubules rearrange to control the orientation of new cellulose microfibrils and determine cell shape.

role of microtubules in cell wall deposition

Role of Microtubules in Cell Wall Deposition

Microtubules are small hollow tubes in eukaryotic cells. The cell wall microtubules are polymerized dimers of two globular proteins, &#945;-tubulin and &#946;-tubulin, two globular proteins. With a diameter of about 25 nm, microtubules are the widest components of the cytoskeleton. They help the cell resist compression and provide a track along which vesicles move through the cell or pull replicated chromosomes to opposite ends of a dividing cell. Microtubules go through quick cycles of disassembly and reassembly.
In plant cells, cortical microtubules are known to play a role in depositing cellulose in the cell wall. They influence cellulose deposition by either moving microtubules or directly changing the orientation of newly synthesized cellulose microfibrils. Microfibrils stabilize the boundaries of specialized plasma membrane domains that force nascent cellulose chains into a parallel alignment through glucan chain polymerization and chain crystallization. The glucose monomers form hydrogen bonds, thus holding the cellulose chains firmly together, forming oriented microfibrils. This imparts rigidity in the cell wall during cellulose deposition.
Adapted from section 4.5 cytoskeleton, openstax AP biology, section 6.4 Prokaryotic cell division, Openstax concepts of biology, section 3.2 Carbohydrates, Openstax biology 2 e.

Microtubules are small hollow tubes in eukaryotic cells. The cell wall microtubules are polymerized dimers of two globular proteins, &#945;-tubulin and ...

role-of-microtubules-in-cell-wall-deposition

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JoVE Core

Cell Biology

Unit 1

Plant Cell Structure and Organization

KEY TERMS AND CONCEPTS

microtubules guide cellulose alignment

Microtubules help organize cellulose as plant cell walls are built. These small hollow tubes are found in eukaryotic cells, and they are made from dimers of two globular proteins, α-tubulin and β-tubulin. At about 25 nm in diameter, microtubules are the widest parts of the cytoskeleton.

Microtubules also support the cell in other ways. They help cells resist compression. They can serve as tracks for vesicle movement through the cell. During cell division, they can help pull replicated chromosomes to opposite ends of the dividing cell.

In plant cells, cortical microtubules are linked to cellulose deposition in the cell wall. They may guide this process by moving with the cell or by changing the direction of newly made cellulose microfibrils. Microfibrils are tiny cellulose bundles that help shape the wall.

These microfibrils mark the edges of special plasma membrane regions. These regions help force new cellulose chains into a parallel layout as glucan chains are made and crystallized. The glucose monomers form hydrogen bonds, which hold the cellulose chains tightly together. This arrangement forms oriented microfibrils and adds rigidity to the cell wall during cellulose deposition.

Microtubules Guide Cellulose Alignment

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Microtubules help organize cellulose as plant cell walls are built. These small hollow tubes are found in eukaryotic cells, and they are made from dimers of two globular proteins, α-tubulin and β-tubulin. At about 25 nm in diameter, microtubules are the widest parts of the cytoskeleton. Microtubules also support the cell in other ways. They help cells resist compression. They can serve as tracks for vesicle movement through the cell. During cell division, they can help pull replicated...

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key terms and concepts

Learn how plant cell cortical microtubules guide cellulose microfibrils, support the cytoskeleton, and help strengthen the cell wall during deposition.

Microtubules Guide Cellulose Alignment | JoVE K12

cell biology

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Microtubules Guide Cellulose Alignment

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