The effector domain of MARCKS Is a nuclear localization signal that regulates cellular PIP2 levels and nuclear PIP2 localization

Academic Article

Abstract

  • © 2015 Rohrbach et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Translocation to the nucleus of diacylglycerol kinase (DGK)- is dependent on a sequence homologous to the effector domain of Myristoylated Alanine Rich C-Kinase Substrate (MARCKS). These data would suggest that MARCKS could also localize to the nucleus. A single report demonstrated immunofluorescence staining of MARCKS in the nucleus; however, further experimental evidence confirming the specific domain responsible for this localization has not been reported. Here, we report that MARCKS is present in the nucleus in GBM cell lines. We then over-expressed wild-type MARCKS (WT) and MARCKS with the effector domain deleted (δED), both tagged with V5-epitope in a GBM cell line with low endogenous MARCKS expression (U87). We found that MARCKS-WT localized to the nucleus, while the MARCKS construct without the effector domain remained in the cytoplasm. We also found that over-expression of MARCKS-WT resulted in a significant increase in total cellular phosphatidyl-inositol (4,5) bisphosphate (PIP2) levels, consistent with prior evidence that MARCKS can regulate PIP2 levels.We also found increased staining for PIP2 in the nucleus with MARCKS-WT over-expression compared to MARCKS δED by immunofluorescence. Interestingly, we observed MARCKS and PIP2 co-localization in the nucleus. Lastly, we found changes in gene expression when MARCKS was not present in the nucleus (MARCKS δED). These data indicate that the MARCKS effector domain can function as a nuclear localization signal and that this sequence is critical for the ability of MARCKS to regulate PIP2 levels, nuclear localization, and gene expression. These data suggests a novel role for MARCKS in regulating nuclear functions such as gene expression. Copyright:
  • Published In

  • PLoS ONE  Journal
  • Digital Object Identifier (doi)

    Pubmed Id

  • 14659859
  • Author List

  • Rohrbach TD; Shah N; Jackson WP; Feeney EV; Scanlon S; Gish R; Khodadadi R; Hyde SO; Hicks PH; Anderson JC
  • Volume

  • 10
  • Issue

  • 10