cytoskeleton

Cytoskeleton

A complex system of protein filaments and tubules located in the cytoplasm of eukaryotic cells, responsible for maintaining the cell's shape, enabling cellular movement, and facilitating intracellular transport.

Actin Filaments

Cytoskeletal filaments composed of the protein actin, measuring about 7 nm in diameter, characterized by their thin, flexible structure, which plays a crucial role in cell movement, division, and maintaining overall cell shape.

Microtubules

Cylindrical tubes with an outer diameter of 25 nm formed from tubulin dimers, serving essential roles in maintaining cell shape, enabling intracellular transport of organelles, and organizing the mitotic spindle during cell division.

Intermediate Filaments

Robust and durable cytoskeletal components approximately 10 nm in diameter that provide mechanical strength and stability to cells, often composed of diverse proteins such as keratin and vimentin, contributing to cell integrity.

Motor Proteins

A group of proteins that utilize chemical energy derived from ATP hydrolysis to produce mobility in cells, facilitating the transport of cellular cargo along cytoskeletal structures, such as microtubules and actin filaments.

Dyneins

Motor proteins specialized for the transport of various cellular cargo toward the minus (-) end of microtubules, playing a vital role in processes such as ciliary and flagellar beating.

Kinesins

Motor proteins that transport cellular cargo toward the plus (+) end of microtubules, often involved in the movement of vesicles, organelles, and other materials within cells.

Treadmilling

A dynamic process in which actin filaments maintain a constant length through a continuous cycle of monomer addition at the plus end and loss at the minus end, crucial for cellular processes such as motility and shape changes.

Capping Proteins

Proteins that bind to the ends of microtubules, stabilizing their structure by preventing further polymerization or depolymerization, thereby regulating microtubule dynamics.

Lamellipodium

Flat, sheet-like extensions at the leading edge of a migrating cell, primarily composed of an actin filament meshwork, facilitating cell movement and interaction with the extracellular environment.

Filopodia

Long, thin, finger-like projections from the cell surface formed by actin filaments, playing a key role in sensing environmental signals and guiding cell movement.

Arp2/3 Complex

A protein complex that initiates the formation of branched actin filament networks, critical for generating the force necessary for cellular protrusions and movement.

Profilin

An actin-binding protein that facilitates the exchange of ADP for ATP on G-actin monomers, promoting actin polymerization and filament growth.

Cofilin

An actin-binding protein that severs actin filaments, playing a crucial role in regulating filament turnover and disassembly, thus influencing cell motility and shape.

Wiskott-Aldrich Syndrome Protein (WASp)

A specialized protein that activates the Arp2/3 complex, promoting the nucleation of new actin filaments, particularly important in immune cells for functioning properly.

G-actin

The globular monomeric form of actin that serves as the building block for filamentous (F-actin) structures, critical in various cellular functions including motility and division.

F-actin

The polymerized filamentous form of actin made up of G-actin monomers, forming a double helical structure that is vital for providing mechanical support and facilitating movement in eukaryotic cells.

GTP Hydrolysis

The biochemical process wherein GTP is converted to GDP, a critical event in the regulation of microtubule dynamics and contributing to their inherent instability, essential for cellular functions.

Centrosome

The central microtubule-organizing center of the cell, comprising a pair of centrioles, crucial for organizing the microtubule network and playing a key role in cell division.

Dynamic Instability

The phenomenon where microtubules undergo rapid phases of growth and shrinkage, governed by the hydrolysis of GTP, crucial for cellular activities such as mitosis.

LINC Complex

The Linker of Nucleoskeleton and Cytoskeleton complex that connects the cytoskeletal framework with the nuclear envelope, allowing for mechanical communication between the two cellular compartments.

Taxol

An anti-cancer drug that stabilizes microtubules by preventing their depolymerization, effectively halting mitosis and thus impacting cell division.

Epidermolysis Bullosa Simplex

A genetic disorder caused by mutations in keratin genes, resulting in fragile skin that easily blisters and tears due to mechanical stress.

Amyotrophic Lateral Sclerosis (ALS)

A progressive neurodegenerative disease characterized by the degeneration of motor neurons, leading to muscle weakness and atrophy, often associated with the accumulation of misfolded neurofilaments.

Kartagener’s Syndrome

A rare genetic condition caused by defects in the dynein motor protein involved in ciliary movement, leading to issues such as chronic respiratory infections and infertility.

Actomyosin

A key contractile apparatus in muscle cells, composed of actin filaments and myosin motor proteins, crucial for muscle contraction and various forms of cellular movement.

Mechanotransduction

The process by which cells detect and respond to mechanical environmental signals, influencing various cellular functions such as growth, differentiation, and response to stimuli.

Nuclear Lamina

A dense fibrillar network composed of intermediate filaments situated underneath the nuclear envelope, providing structural support and regulating essential nuclear processes.

Keratinocytes

The predominant cell type found in the epidermis, responsible for forming the outer protective layer of skin, relying on actin filaments for structural support and movement.

Cell Cortex

A specialized region located just beneath the cell membrane, enriched with actin filaments, playing a crucial role in maintaining cell shape and facilitating movement.

Cell Migration

The process by which cells move from one location to another, typically involving dynamic rearrangements of the cytoskeleton and driven by various signaling pathways.

Vesicular Transport

The method by which cellular cargo is transported in vesicles, often involving motor proteins that navigate along microtubules, crucial for processes like secretion and endocytosis.

Myosin

A class of motor proteins that convert chemical energy in the form of ATP into mechanical energy, facilitating muscle contraction and the movement of actin filaments.