Mitotic Spindle Proteomics in Chinese Hamster Ovary Cells

Abstract

Mitosis is a fundamental process in the development of all organisms. The mitotic spindle guides the cell through mitosis as it mediates the segregation of chromosomes, the orientation of the cleavage furrow, and the progression of cell division. Birth defects and tissue-specific cancers often result from abnormalities in mitotic events. Here, we report a proteomic study of the mitotic spindle from Chinese Hamster Ovary (CHO) cells. Four different isolations of metaphase spindles were subjected to Multi-dimensional Protein Identification Technology (MudPIT) analysis and tandem mass spectrometry. We identified 1155 proteins and used Gene Ontology (GO) analysis to categorize proteins into cellular component groups. We then compared our data to the previously published CHO midbody proteome and identified proteins that are unique to the CHO spindle. Our data represent the first mitotic spindle proteome in CHO cells, which augments the list of mitotic spindle components from mammalian cells.

PGRMC1 participates in late events of bovine granulosa cells mitosis and oocyte meiosis

“…Previous works demonstrate that PGRMC1 specifically localizes to the mitotic spindle apparatus of different cell lines, 11,16,17 where it directly interacts with b tubulin and controls spindle microtubule stability. 11 The present study demonstrates that PGRMC1 directly interacts also with AURKB and that the extent of this interaction is highest during the final phase of granulosa cell division.…”

“…13,15 However, PGRMC1 is also found in other sub-cellular compartments where it probably exerts additional functions. In particular PGRMC1 associates to the mitotic spindle, 11,16,17 where it directly interacts with b tubulin 11 suggesting a role in the regulation of mitosis. Immunofluorescence studies have shown that PGRMC1 changes its localization dynamically during mitosis: it associates with the spindle apparatus in metaphase, while it localizes to the midzone and the midbody in anaphase and telophase/cytokinesis.…”

PGRMC1 and the faithful progression through mitosis and meiosis

“…3 Interestingly, one protein that localizes to the mid-zone/mid-body is progesterone receptor membrane component-1 (PGRMC1). 4 This protein was initially identified in liver as a progesterone binding protein, which accounts for its name (For review see Cahill 5 ). However, PGRMC1 is expressed in many cell types and has progesterone dependent and independent actions depending in part on its cellular location.…”

Association of Maternal mRNA and Phosphorylated EIF4EBP1 Variants With the Spindle in Mouse Oocytes: Localized Translational Control Supporting Female Meiosis in Mammals

“…Recent studies in Xenopus revealed enriched localization to spindle microtubules of mRNAs encoding spindle proteins (Blower et al 2007). The spindle is a complex structure; proteomic studies of isolated spindles have identified .1100 spindle-associated proteins, of which nearly 400 are specific to spindles and shared with proteomic studies that incorporated DNAse digests to deplete DNA-associated proteins (Sauer et al 2005;Bonner et al 2011), indicating that a large array of proteins is needed to support spindle formation, maintenance, and function. Localized maternal mRNAs could be translated in situ to provide a local high concentration of proteins, while minimizing potential deficiencies related to limitations in the speed or extent of protein accumulation from elsewhere within the ooplasm.…”