Protein translation refers to the process of decoding the nucleotide sequence of mRNAs into proteins in the cytoplasm of eukaryotic cells. The initiation phase of the translation has long been recognized as a key regulatory step however, recently a growing amount of evidence indicated the importance of fine-tuning the elongation phase as well. In this thesis I present the results of my studies, which focused on the regulatory role of a new type of granules that contain the Not proteins of the Ccr4-Not complex in translation elongation dynamics in S. cerevisiae. Specifically, in the first study, we described the existence of heavy particles containing ribosome nascent chain complexes and Not1. Such “Not1 condensates”, subsequently termed as “Not1-containing Assemblysomes”, are important for protecting translating but paused ribosomes to enable co-translation association of encoded subunits. In the second study, we uncovered the roles of Not4 and Not5 as regulators of translation elongation dynamics.