Cytoskeleton-associated large RNP complexes in tobacco male gametopyte (EPPs) are associated with ribosomes and are involved in protein synthesis, processing and localisation
Abstract
The progamic phase of male gametophyte development involves activation of synthetic and catabolic processes required for the rapid growth of the pollen tube. It is well-established that both transcription and translation play an important role in global and specific gene expression patterns during pollen maturation.
On the contrary, germination of many pollen species has been shown to be largely independent of transcription but vitally dependent on translation of stored mRNAs. Here, we report the first structural and proteomic data about large ribonucleoprotein particles (EPPs) in tobacco male gametophyte.
These complexes are formed in immature pollen where they contain translationally silent mRNAs. Although massively activated at the early progamic phase, they also serve as a long-term storage of mRNA transported along with the translational machinery to the tip region.
Moreover, EPPs were shown to contain ribosomal subunits, rRNAs and a set of mRNAs.