Pathways & interactions
Short name: Coronin
Overlapping homologous superfamilies
Coronins are evoluntionarily conserved WD-repeat-containing proteins mostly involved in actin cytoskeleton organisation. The WD40 motif is found in a multitude of eukaryotic proteins involved in a variety of cellular processes [PMID: 11761326]. Repeated WD40 motifs act as a site for protein-protein interaction, and proteins containing WD40 repeats are known to serve as platforms for the assembly of protein complexes or mediators of transient interplay among other proteins. The final 40 amino acids are predicted to form a coiled-coil in a coronin homodimer [PMID: 10461187].
Coronin was first identified as an actin binding protein in Dictyostelium discoideum. It was named Coronin because of its association with crown-shaped cell surface projections of growth-phase D [PMID: 1661669]. Since then, several Coronin homologues and isoforms have been identified from yeast to human. Mammalian Coronin isoforms include Coronin 1A/B/C, Coronin 2A/B, Coronin 6 and Coronin 7. The yeast Coronin homologue is known as Crn1, while the Drosophila homologue is known as pod1.
In budding yeast, Crn1 regulates the actin filament nucleation/branching activity of the actin-related protein 2/3 (Arp2/3) complex through interaction with the Arc35p subunit [PMID: 12499356].
Mammalian Coronin 1A is exclusively expressed in leukocytes and involved in the regulation of leukocyte specific signaling events [PMID: 18925376]. The crystal structure of Coronin 1A has been solved [PMID: 16407068, PMID: 18925371]. Mammalian Coronin 1B can protect new (ATP-rich) filaments from F-actin severing Cofilin and dismantle old (ADP-rich) filaments by inducing Arp2/3 dissociation in lamellipodia [PMID: 18775315, PMID: 17350576].
It is worth noting that Coronin 7 in this entry has not been shown to interact with actin [PMID: 15892111]. Unlike most of the Coronin isoforms, it binds to the outer side of Golgi complex membranes and acts as a mediator of cargo vesicle formation at the trans-Golgi network [PMID: 18925375].
- PTHR10856 (PTHR10856)