Disease relevance of MPHOSPH1

• Autoantibodies from patients with idiopathic ataxia bind to M-phase phosphoprotein-1 (MPP1) [1].

High impact information on MPHOSPH1

• The deduced MPP1 and MPP2 amino acid sequences are not closely related to any previously described proteins [2].
• We conclude that MPP1 is a new mitotic molecular motor required for completion of cytokinesis [3].
• In cycling cells, MPP1 localizes mainly to the nuclei in interphase [3].
• MPP1 suppression by RNA interference induces failure of cell division late in cytokinesis [3].
• During mitosis, MPP1 is diffuse throughout the cytoplasm in metaphase and subsequently localizes to the midzone to further concentrate on the midbody [3].

Biological context of MPHOSPH1

• Immunofluorescence analysis showed that endogenous KRMP1 was localized predominantly to the cytoplasm during interphase and dispersed throughout the cell during mitosis [4].
• An in vivo labeling experiment revealed that KRMP1 is phosphorylated, and we also found that the region within the tail domain containing Thr-1604 as the cdc2 kinase phosphorylation site differs from the bimC box conserved in the bimC subfamily of KRPs [4].
• The nucleotide sequence was 99% identical to MPP1, a cell-cycle-related nuclear protein phosphorylated during mitosis [1].

Anatomical context of MPHOSPH1

• In gliding experiments using polarity-marked microtubules, MPP1 is a slow molecular motor that moves toward the microtubule plus-end at a 0.07 microm/s speed [3].
• Overexpression of KRMP1 caused COS-7 cells to arrest at G(2)-M, and co-expression of Pin1 reversed this effect, indicating their physiological interaction [4].

Associations of MPHOSPH1 with chemical compounds

• Analysis of the deduced amino acid sequences revealed that KRMP have a high proportion of lysine, glycine, and tyrosine, and their predict isoelectric points are higher than any other identified shell matrix protein to our knowledge [5].
• The deduced amino acid sequences of KRMP can be divided into three regions, including an N-terminal signal peptide, a lysine-rich basic region interacting with acidic proteins or CO(3)(2-), and a Gly/Tyr-rich region involved in the protein cross-link via quinone-tanning process [5].

Regulatory relationships of MPHOSPH1

• Together, our results suggest that KRMP1 is a mitotic target regulated by Pin1 and vice versa [4].

Other interactions of MPHOSPH1

• Identification of a novel kinesin-related protein, KRMP1, as a target for mitotic peptidyl-prolyl isomerase Pin1 [4].
• Partial-length cDNAs encoding two MPM2-reactive proteins termed MPM2-reactive phosphoproteins 1 and 2 (MPP1 and MPP2) were isolated [2].

Analytical, diagnostic and therapeutic context of MPHOSPH1

• RT-PCR and in situ hybridization demonstrated that KRMP mRNA was specifically expressed in the mantle edge, involved in the prismatic layer formation [5].

References