HAFIDH, Said, POTĚŠIL, D., ZDRÁHAL, Z., HONYS, David. DEAD-Box RNA Helicases are among the Constituents of the Tobacco Pollen mRNA Storing Bodies. Journal of Plant Biochemistry and Physiology. 2013, 1(3). ISSN 2329-9029

Male gametogenesis in flowering plants is attributed by substantial changes in cellular reorganization, cell fate specification and changes in cellular metabolism including RNA metabolism. Sequestration from immediate translation of protein coding mRNAs has emerged as one aspect of mRNA post transcriptional regulation that is widespread during gametogenesis. Transcripts repressed from translation are confiscated into mRNA storing bodies and function later during development and at early stages of embryogenesis. In Arabidopsis, 88% and 12% of the zygotic transcriptome at 2-4 cells stage of development now known to originate from maternal and paternal gametes respectively. Moreover, an activator of YODA (YDA) mitogen-activated protein kinase pathway in the zygote, the interleukin-1 receptor-associated kinase (IRAK)/Pelle-like kinase gene Short Suspensor (SSP) is specifically expressed in the Arabidopsis male gametophyte but only translated upon gamete fusion to promote suspensor development. Previously we have reported the proteome of EPP complexes, the tobacco pollen large mRNPs granules containing translationally sequestered mRNAs, non-coding smRNAs and a repertoire of associated protein complexes including factors for initiation of translation. Here, we have analysed our previous and new EPP proteome data set obtained from orbitrap LC-MS/MS as well as tobacco pollen Agilent microarray data and highlighted that RNA helicases, predominantly DEAD-box domain containing helicases are among the constituents of the EPP RNA granules. Their potential function tied to local translation is explored. In addition, we discuss the recent report of RNA helicases localization within peroxisomes bodies and speculate their likely role as an additional site for mRNA control in the male gametophyte alongside EPP mRNA storing granules. Thus, mRNA homeostasis in the male gametophyte might be subjected to multiple controls at diverse but likely interconnected cytoplasmic foci.