The two types of dynein are cytoplasmic dyneins and axonemal dyneins, which are also called ciliary or flagellar dyneins.
Dyneins are a family of cytoskeletal motor proteins that move along microtubules in cells which convert the chemical energy stored in ATP to mechanical work.
Dynein transports various cellular cargos, provides forces and displacements important in mitosis, and drives the beat of eukaryotic cilia and flagella.
Phylogenetically, there are nine major classes of dynein heavy chain20.
The cytoplasmic dynein 1 heavy chain (encoded by DYNC1H1 in humans) is used for nearly all of the minus end-directed transport in the cytoplasm of most eukaryotic cells.
Cytoplasmic dynein-1 is responsible for the majority of transport toward microtubule minus ends in the cell interior.
Dynein-2, also known as intraflagellar transport dynein, moves cargoes along the axoneme of eukaryotic cilia and flagella.
Dynein is unique compared with kinesin and myosin because dynein molecules form large molecular complexes.
For example, one axonemal outer arm dynein molecule of C. reinhardtii is composed of three dynein heavy chains, two intermediate chains, and more than ten light chains.
Dyneins make up a family of AAA+ motors that move toward the minus end of microtubules.
Cytoplasmic dynein is responsible for transporting intracellular cargos in interphase cells and mediating spindle assembly and chromosome positioning during cell division.
The flagellar dyneins, also called axonemal dyneins, are the arms that project from the doublet axonemal microtubules of flagella and cilia.
The flagellar dyneins generate the sliding force between outer doublet microtubules that is converted by other axonemal structures into the bending of cilia and flagella.
Kinesin motor proteins are innately limited to unidirectional stepping, allowing for either anterograde or retrograde transport, with most kinesins performing anterograde transport.
Meanwhile, dynein is more likely to perform retrograde transport, although dynein motor proteins are capable of bidirectional stepping.