Bloch, DonaldLi, PingchengBloch, Emily G.Berenson, Daniel F.Galdos, Rita L.Arora, PankajMalhotra, RajeevWu, ConnieYang, Weihong2014-05-062014Bloch, Donald B., Pingcheng Li, Emily G. Bloch, Daniel F. Berenson, Rita L. Galdos, Pankaj Arora, Rajeev Malhotra, Connie Wu, and Weihong Yang. 2014. “LMKB/MARF1 Localizes to mRNA Processing Bodies, Interacts with Ge-1, and Regulates IFI44L Gene Expression.” PLoS ONE 9 (4): e94784. doi:10.1371/journal.pone.0094784. http://dx.doi.org/10.1371/journal.pone.0094784.1932-6203http://nrs.harvard.edu/urn-3:HUL.InstRepos:12152990The mRNA processing body (P-body) is a cellular structure that regulates the stability of cytoplasmic mRNA. MARF1 is a murine oocyte RNA-binding protein that is associated with maintenance of mRNA homeostasis and genomic stability. In this study, autoantibodies were used to identify Limkain B (LMKB), the human orthologue of MARF1, as a P-body component. Indirect immunofluorescence demonstrated that Ge-1 (a central component of the mammalian core-decapping complex) co-localized with LMKB in P-bodies. Two-hybrid and co-immunoprecipitation assays were used to demonstrate interaction between Ge-1 and LMKB. The C-terminal 120 amino acids of LMKB mediated interaction with Ge-1 and the N-terminal 1094 amino acids of Ge-1 were required for interaction with LMKB. LMKB is the first protein identified to date that interacts with this portion of Ge-1. LMKB was expressed in human B and T lymphocyte cell lines; depletion of LMKB increased expression of IFI44L, a gene that has been implicated in the cellular response to Type I interferons. The interaction between LMKB/MARF1, a protein that contains RNA-binding domains, and Ge-1, which interacts with core-decapping proteins, suggests that LMKB has a role in the regulation of mRNA stability. LMKB appears to have different functions in different cell types: maintenance of genomic stability in developing oocytes and possible dampening of the inflammatory response in B and T cells.en-USBiology and life sciencesBiochemistryProteinsProtein InteractionsRNARNA stabilityNucleic AcidsProteomicsCell BiologyCellular Structures and OrganellesCytoplasmMolecular Cell BiologyGeneticsGene ExpressionJournal Article2014-05-0610.1371/journal.pone.0094784