leading edge of lamellipodium
Definition
Target type: cellularcomponent
That part of the lamellipodium which represents the distal part of the structure. [PMID:22339865]
The leading edge of the lamellipodium is a dynamic and highly specialized cellular structure responsible for cell motility. It is characterized by a mesh-like network of branched actin filaments, referred to as the "actin meshwork," which provides the structural basis for the protrusion of the plasma membrane. This meshwork is constantly being assembled and disassembled, with new actin filaments being polymerized at the leading edge and older filaments being depolymerized further back in the cell. The actin meshwork is interconnected with other key components, including:
1. **Actin-binding proteins:** These proteins regulate the assembly and disassembly of actin filaments, controlling the dynamics of the meshwork. Some examples include Arp2/3 complex, which nucleates new actin filaments, and cofilin, which severs and depolymerizes filaments.
2. **Plasma membrane:** The plasma membrane at the leading edge is highly enriched in lipids and proteins that promote adhesion and signaling. This membrane is continuously being added to as the cell protrudes, and it is also involved in the uptake of extracellular signals that guide cell movement.
3. **Adhesion molecules:** Integrins and other adhesion molecules bind to the extracellular matrix (ECM) and provide traction for cell movement. These molecules are clustered at the leading edge, where they are involved in both adhesion and signaling.
4. **Signaling molecules:** The leading edge is a hub for signaling pathways that regulate cell motility. These pathways involve a variety of molecules, including small GTPases like Rac and Cdc42, which are essential for actin polymerization and lamellipodial protrusion.
This complex interplay of components creates a dynamic and highly regulated structure that is essential for cell migration. The leading edge of the lamellipodium is constantly adapting to changes in the environment, allowing cells to navigate through tissues and respond to cues from their surroundings.'
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Proteins (2)
| Protein | Definition | Taxonomy |
|---|---|---|
| 14 kDa phosphohistidine phosphatase | A 14 kDa phosphohistidine phosphatase that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q9NRX4] | Homo sapiens (human) |
| Dual specificity protein phosphatase 22 | A dual specificity protein phosphatase 22 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q9NRW4] | Homo sapiens (human) |
Compounds (7)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| acetarsol | acetamides; anilide | ||
| ethacrynic acid | etacrynic acid : An aromatic ether that is phenoxyacetic acid in which the phenyl ring is substituted by chlorines at positions 2 and 3, and by a 2-methylidenebutanoyl group at position 4. It is a loop diuretic used to treat high blood pressure resulting from diseases such as congestive heart failure, liver failure, and kidney failure. It is also a glutathione S-transferase (EC 2.5.1.18) inhibitor. Ethacrynic Acid: A compound that inhibits symport of sodium, potassium, and chloride primarily in the ascending limb of Henle, but also in the proximal and distal tubules. This pharmacological action results in excretion of these ions, increased urinary output, and reduction in extracellular fluid. This compound has been classified as a loop or high ceiling diuretic. | aromatic ether; aromatic ketone; dichlorobenzene; monocarboxylic acid | EC 2.5.1.18 (glutathione transferase) inhibitor; ion transport inhibitor; loop diuretic |
| ethylmaleimide | Ethylmaleimide: A sulfhydryl reagent that is widely used in experimental biochemical studies. | maleimides | anticoronaviral agent; EC 1.3.1.8 [acyl-CoA dehydrogenase (NADP(+))] inhibitor; EC 2.1.1.122 [(S)-tetrahydroprotoberberine N-methyltransferase] inhibitor; EC 2.7.1.1 (hexokinase) inhibitor |
| roxarsone | roxarsone : An organoarsonic acid where the organyl group is 4-hydroxy-3-nitrophenyl. Roxarsone: An arsenic derivative which has anticoccidial action and promotes growth in animals. | 2-nitrophenols; organoarsonic acid | agrochemical; animal growth promotant; antibacterial drug; coccidiostat |
| stictic acid | stictic acid: antioxidant from lichen, Usnea articulata; structure in first source | aromatic ether | |
| illudalic acid | illudalic acid: isolated from Clitocybe illudens; structure in first source | ||
| norstictic acid | norstictic acid: from Xanthoparmelia chlorochroa; structure in first source |