Various AKIP1 expression levels affect its subcellular localization but have no effect on NF-kappaB activation

Physiol Res. 2019 Jun 30;68(3):431-443. doi: 10.33549/physiolres.933961. Epub 2019 Mar 22.

Abstract

A-kinase interacting protein 1 (AKIP1) has been shown to interact with a broad range of proteins involved in various cellular processes, including apoptosis, tumorigenesis, and oxidative stress suggesting it might have multiple cellular functions. In this study, we used an epitope-tagged AKIP1 and by combination of immunochemical approaches, microscopic methods and reporter assays we studied its properties. Here, we show that various levels of AKIP1 overexpression in HEK-293 cells affected not only its subcellular localization but also resulted in aggregation. While highly expressed AKIP1 accumulated in electron-dense aggregates both in the nucleus and cytosol, low expression of AKIP1 resulted in its localization within the nucleus as a free, non-aggregated protein. Even though AKIP1 was shown to interact with p65 subunit of NF-kappaB and activate this transcription factor, we did not observe any effect on NF-kappaB activation regardless of various AKIP1 expression level.

MeSH terms

  • Adaptor Proteins, Signal Transducing / biosynthesis*
  • Adaptor Proteins, Signal Transducing / genetics
  • Cell Nucleus / chemistry
  • Cell Nucleus / metabolism*
  • Cytosol / chemistry
  • Cytosol / metabolism*
  • Gene Expression Regulation
  • HEK293 Cells
  • Humans
  • Mitochondria / chemistry
  • Mitochondria / metabolism*
  • NF-kappa B / analysis
  • NF-kappa B / metabolism*
  • Nuclear Proteins / biosynthesis*
  • Nuclear Proteins / genetics
  • Subcellular Fractions / chemistry
  • Subcellular Fractions / metabolism*

Substances

  • AKIP1 protein, human
  • Adaptor Proteins, Signal Transducing
  • NF-kappa B
  • Nuclear Proteins