Disease relevance of RPS27

• The MPS-1 gene is expressed at relatively high levels in several human carcinoma cell lines, particularly those derived from ectodermal layers, and at higher levels in melanomas (ontogenically of neural origin) [1].
• The protein product of the human Metallopanstimulin (MPS-1) gene was produced in the insect cell line Spodoptera frugiperda (Sf9) using the baculovirus expression vector system Autographa californica nuclear polyhedrosis virus (AcNPV) [2].
• These data suggest that MPS-1 could be applicable to the immunotherapy of breast cancer [3].
• However, it is unclear whether MPS-1 plays any role in gastric cancer development or progression [4].
• In this paper, we present a case of overexpression of MPS-1 in colon cancer tissues of a seventeen year old male [5].

High impact information on RPS27

• We propose that MPS1-dependent BLM phosphorylation is important for ensuring accurate chromosome segregation, and its deregulation may contribute to cancer [6].
• MPS1-dependent mitotic BLM phosphorylation is important for chromosome stability [6].
• Using immunodepletion approach and a rephosphorylation assay in Xenopus extracts, we report here that not only the formation of the 3F3/2 phosphoepitope is dependent on the checkpoint activation but also the loading of the 3F3/2 substrate to kinetochores requires the prior assembly of Mps1, Bub1 and BubR1 onto kinetochores [7].
• Metaphase arrest by cyclin e-cdk2 requires the spindle-checkpoint kinase mps1 [8].
• Consistent with the recently identified vertebrate MPS1 homologues, we found that hMPS1 is localized to centrosomes and kinetochores [9].

Biological context of RPS27

• We localized the kinetochore targeting domain in hMPS1 and found that it can abrogate the mitotic checkpoint in a dominant negative manner [9].
• The carboxyl-terminal cysteine arrangement in hRPS27 is similar to the family of C4 zinc finger DNA-binding proteins [10].
• A potential polyadenylation signal AACAAA is found in the MPS-1 cDNA but the more frequently used AATAAA sequence is present in the hRPS27 cDNA [10].
• In contrast, the MPS-1 mRNA is expressed at low levels in normal WI-38 human lung diploid fibroblasts in culture [1].
• Moreover, little is presently known about the regulation of Mps1 kinases during the cell cycle [11].

Anatomical context of RPS27

• Characterization of the MPS-1 protein extracted from Sf9 infected cells showed that it: binds zinc ions specifically; is phosphorylated; accumulates in the nucleus; is tightly bound to the nucleus; and binds to calf thymus DNA-cellulose [2].
• Kinetochore localization and microtubule interaction of the human spindle checkpoint kinase Mps1 [11].
• In contrast, no expression of MPS-1 was observed in the adjacent normal mucosa [5].

Associations of RPS27 with chemical compounds

• These results support the hypothesis that the MPS-1 protein may act, at least in part, by interacting with genes possessing the cyclic AMP-responsive element sequence [2].
• Furthermore, we have shown that detection of MPS-N immunoreactive material in sera corresponding to the NH2 terminus of MPS-1 provides a method for determining the presence of certain types of abnormal proliferative conditions and/or active oncogenic processes in patients [12].

Other interactions of RPS27

• The mRNA for MPS-1 was induced in MDA-468 cells by fetal calf serum, TGF-beta 1, TGF-beta 2, and cAMP analogues [1].

Analytical, diagnostic and therapeutic context of RPS27

• We report here the primary structures and sequence analysis of the human ribosomal protein L39 (hRPL39) and S27 (hRPS27) [10].
• The MPS-1 protein constitutes one of the major proteins in the nuclear fraction of Sf9 cells and can be purified from this source to near homogeneity by a two-step procedure composed of high-performance liquid chromatography and gel electrophoresis [2].
• Finally, recombinant MPS-1 generated a specific protein-DNA complex with a duplex oligomer containing a cyclic AMP-responsive element, as assessed by gel mobility shift assays [2].
• Screening of tissue specimens by immunohistochemistry revealed 50.4% positive for MPS-1 in 125 cancer patients [3].
• In Western blot analysis, MPS-1 was easily detected strongly in actively proliferating cells and three breast cancer cell lines [3].

References