InterPro domain: IPR007145

This is a family of microtubule associated proteins, including MAP65 (MAP65-1/2/3/4/5/6/7/8/9) from Arabidopsis, Ase1 from yeast, and PRC1 from mammals.

Ase1 is required for spindle elongation and stabilisation. It is cell cycle-regulated by anaphase promoting complex [ 1 ]. It is a potential Cdc28p substrate [ 2 ].

MAP65-1 plays a role in stabilising anti-parallel microtubules in the central spindle at anaphase to early cytokinesis. MAP65-1 is cell cycle regulated by phosphorylation [ 3 , 4 , 5 , 6 , 7 ].

PRC1 is a microtubule binding and bundling protein essential to maintain the mitotic spindle midzone [ 8 ]. It is a key regulator of cytokinesis that cross-links antiparallel microtubules at an average distance of 35 nM [ 9 , 10 ]. PRC1 is also required for KIF14 (a kinesin-3 family motor protein) localisation to the central spindle and midbody [ 11 , 12 , 13 ] and is required to recruit PLK1 to the spindle. It stimulates PLK1 phosphorylation of RACGAP1/HsCyk-4 to allow recruitment of ECT2 to the central spindle [ 14 ].

1. The molecular function of Ase1p: evidence for a MAP-dependent midzone-specific spindle matrix. Microtubule-associated proteins. J. Cell Biol. 160, 517-28
2. Targets of the cyclin-dependent kinase Cdk1. Nature 425, 859-64
3. Dynamic interaction of NtMAP65-1a with microtubules in vivo. J. Cell. Sci. 118, 3195-201
4. Two microtubule-associated proteins of the Arabidopsis MAP65 family function differently on microtubules. Plant Physiol. 138, 654-62
5. Modulated targeting of GFP-AtMAP65-1 to central spindle microtubules during division. Plant J. 43, 469-78
6. MAP65: a bridge linking a MAP kinase to microtubule turnover. Curr. Opin. Plant Biol. 9, 563-70
7. Control of the AtMAP65-1 interaction with microtubules through the cell cycle. J. Cell. Sci. 119, 3227-37
8. PRC1 is a microtubule binding and bundling protein essential to maintain the mitotic spindle midzone. J. Cell Biol. 157, 1175-86
9. Insights into antiparallel microtubule crosslinking by PRC1, a conserved nonmotor microtubule binding protein. Cell 142, 433-43
10. PRC1: a human mitotic spindle-associated CDK substrate protein required for cytokinesis. Mol. Cell 2, 877-85
11. Essential roles of KIF4 and its binding partner PRC1 in organized central spindle midzone formation. EMBO J. 23, 3237-48
12. Cell cycle-dependent translocation of PRC1 on the spindle by Kif4 is essential for midzone formation and cytokinesis. Proc. Natl. Acad. Sci. U.S.A. 102, 343-8
13. KIF14 and citron kinase act together to promote efficient cytokinesis. J. Cell Biol. 172, 363-72
14. Polo-like kinase 1 directs assembly of the HsCyk-4 RhoGAP/Ect2 RhoGEF complex to initiate cleavage furrow formation. PLoS Biol. 7, e1000110