CELLULAR MOVEMENT

Microtubule-based movements

Movements that occur due to the motor proteins that attach themselves to the scaffolding provided by microtubules in cells.

Kinesins and Dyneins

Motor proteins involved in intracellular cargo transport along microtubules. Kinesins are outbound and transport towards the plus end, while Dyneins are inbound and transport towards the minus end.

Cilia and Flagella

Cellular structures involved in cellular movements. Cilia are short, hair-like structures that move in coordinated patterns, while flagella are longer and fewer in number.

Microfilament-based movements

Movements that occur due to the motor proteins that attach themselves to the scaffolding provided by microfilaments in cells.

Myosin motor proteins

Motor proteins involved in muscle cell contractility and non-muscle cell motility.

Contractility

The shortening of muscle cells.

Motility

Movement that occurs at the tissue, cellular, and sub-cellular levels.

Motor proteins

Proteins that convert chemical energy (ATP) into mechanical energy and facilitate movement along filaments.

Outbound

Transport towards the plus end of microtubules.

Inbound

Transport towards the minus end of microtubules.

Microtubule-Associated Motor Proteins

Motor proteins that facilitate traffic along microtubules.

Dyneins

Inbound motor proteins that transport towards the minus end of microtubules. There are two types:Cytoplasmic dyneins and Axonemal dyneins.

Cytoplasmic Dyneins

Dyneins that move cargo towards minus ends and are involved in Retrograde axonal transport.

Axonemal Dyneins

Dyneins that activate microtubule sliding in flagella and cilia.

Kinesins

Outbound motor proteins that transport towards the plus end of microtubules. There are different types with specific functions.

Kinesin-1

Kinesin involved in Anterograde axonal transport.

Kinesin-3

Kinesin that moves synaptic vesicles in neurons.

Kinesin-5

Kinesin responsible for the bidirectional sliding of microtubules during anaphase of mitosis.

Kinesin-6

Kinesin involved in completing cytokinesis.

Kinesin-13

Kinesin that destabilizes the plus ends of microtubules.

Kinesin-14

Kinesin that helps with the formation of the spindle in meiosis and mitosis and moves towards minus ends of microtubules.

Kinesin Walking

The step-wise movement of kinesins along microtubules, powered by ATP binding, hydrolysis, and ADP release.

Kinesin-1

A heterotetramer involved in outbound ATP-dependent transport, converting ATP into work.

AAA+

ATPase Associated with diverse cellular Activities. The rotation of AAA+ drives the lever arm to pull cargo in the direction of the minus-end of microtubules.

Endomembrane Transport

Transport of cargo through the endomembrane system using kinesins for anterograde transport and dyneins for retrograde transport.

Axoneme Structure

The bundled doublet microtubule structure shared by cilia and flagella.

Situs Inversus Totalis

A condition caused by mutations in axonemal dyneins, resulting in the mirroring of symmetry of organs.

Microfilament-Based Motility

Movements that occur due to the motor proteins that attach themselves to the scaffolding provided by microfilaments in cells.

Myosin II

Motor protein involved in sliding microfilaments in muscle and muscle contractility.

Myosin V

Motor protein involved in vesicle positioning and trafficking.

Myosin VI

Motor protein involved in endocytosis, moves towards minus ends of microfilaments.

Sarcomere

The contractile unit in muscle cells, consisting of parallel fibers of thin actin filaments and thick myosin filaments that slide against each other during muscle contraction.

Skeletal Muscle Structure

Muscle fibers that contain bundles of myofibrils, which in turn contain thick myosin filaments and thin actin filaments arranged in sarcomeres.

I Bands

Isotropic bands in striated muscle.

A Bands

Anisotropic bands in striated muscle, representing the contractile structure and containing the M-line.

Troponins

Proteins that bind along thin filaments and regulate myosin interactions.

Sarcomere Structural Proteins

Proteins involved in anchoring and stabilizing the sarcomere structure, including CapZ, myomesin, nebulin, and titin.

Neurons

Cells that release acetylcholine at the neuromuscular junction, triggering muscle cell depolarization.

Smooth Muscle

Non-striated muscle responsible for slow and prolonged contractions, regulated by Ca2+.

Cytoplasmic Streaming

Movement of organelles through the cytoplasm driven by actin-myosin dynamics.