mitotic interactor & substrate of PLK1; mitotic spindle positioning protein (MISP C19orf21)

Function

• role in mitotic spindle orientation & mitotic progression
• regulates distribution of dynactin at the cell cortex (PLK1-dependent) thus stabilizing cortical & astral microtubule attachments required for proper mitotic spindle positioning
• may link microtubules to the actin cytospkeleton & focal adhesions
• may be required for directed cell migration & centrosome orientation
• may also be necessary for proper stacking of the Golgi
• phosphorylated by CDK1 & PLK1
• CDK1 is the priming kinase for PLK1 phosphorylation
• phosphorylation by PLK1 is required for proper spindle orientation at metaphase
• associates with F-actin
• interacts with DCTN1
  • interaction regulates DCTN1 distribution at the cell cortex
• interacts with PTK2/FAK & MAPRE1

Compartment

• cell junction, focal adhesion
• cytoplasm, cytoskeleton, cell cortex
• predominantly localizes to cortical actin structures during interphase & mitosis
• present in retraction fibers, which are formed at former adhesion sites during mitosis, & at spicular membrane protrusions in re-attaching cytokinetic cells
• partially colocalizes with cytoplasmic F-actin
• not detected at microtubules at interphase, nor at spindle during mitosis

Expression

• regulated in a cell-cycle dependent manner
• weakly expressed in G1 & S phases
• expression increases in G2/M phases & persisting until the end of mitosis (at protein level)

More general terms

• phosphoprotein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=126353
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:126353
• OMIM: https://mirror.omim.org/entry/615289
• UniProt: http://www.uniprot.org/uniprot/Q8IVT2.html