1. Home
    2. Journals
    3. Journal of Biosciences
    4. Volume 41
    5. Issue 1

    • Fulltext

       

        Click here to view fulltext PDF


      Permanent link:
      https://www.ias.ac.in/article/fulltext/jbsc/041/01/0051-0062

    • Keywords

       

      Entamoeba histolytica; Nucleolus; rDNA; RNA polymerase I; rRNA transcription

    • Abstract

       

      Initiation of rDNA transcription requires the assembly of a specific multi-protein complex at the rDNA promoter containing the RNA Pol I with auxiliary factors. One of these factors is known as Rrn3P in yeast and Transcription Initiation Factor IA (TIF-IA) in mammals. Rrn3p/TIF-IA serves as a bridge between RNA Pol I and the pre-initiation complex at the promoter. It is phosphorylated at multiple sites and is involved in regulation of rDNA transcription in a growth-dependent manner. In the early branching parasitic protist Entamoeba histolytica, the rRNA genes are present exclusively on circular extra chromosomal plasmids. The protein factors involved in regulation of rDNA transcription in E. histolytica are not known. We have identified the E. histolytica equivalent of TIF-1A (EhTIF-IA) by homology search within the database and was further cloned and expressed. Immuno-localization studies showed that EhTIF-IA co-localized partially with fibrillarin in the peripherally localized nucleolus. EhTIF-IA was shown to interact with the RNA Pol I-specific subunit RPA12 both in vivo and in vitro. Mass spectroscopy data identified RNA Pol I-specific subunits and other nucleolar proteins to be the interacting partners of EhTIF-IA. Our study demonstrates for the first time a conserved putative RNA Pol I transcription factor TIF-IA in E. histolytica.

    • Author Affiliations

       

      Ankita Srivastava1 Alok Bhattacharya2 Sudha Bhattacharya1 Gagan Deep Jhingan3

      1. School of Environmental Sciences,Jawaharlal Nehru University, New Mehrauli Road, New Delhi 110 067, India
      2. School of Life Sciences, Jawaharlal Nehru University, New Mehrauli Road, New Delhi 110 067, India
      3. National Institute of Immunology, Aruna Asaf Ali marg, New Delhi 110 067, India

    • Dates

       
      Published
      March 2016

    • Supplementary Material

       

  • Journal of Biosciences | News

      Forthcoming Special issue.


    • To trigger further research on plant mitochondria, the Journal of Biosciences is bringing out a special issue titled "Plant Mitochondria: Properties and Interactions with Other Organelles".


      Plant mitochondria are quite distinct and have unique features, such as a cyanide-insensitive alternate pathway. They also interact with chloroplasts to optimize photosynthetic carbon assimilation.


      Submissions are welcome until 30 July 2023. The contributions can be original articles, short communications, reviews, or mini-reviews on any topic related to plant mitochondria.


      Authors can submit their articles online at https://www.editorialmanager.com/jbsc/default2.aspx

      Posted on April 12, 2023
      <

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2023-2024 Indian Academy of Sciences, Bengaluru.

Contact | Site index