Tetrapeptide 60–63 of human ribosomal protein uS3 is crucial for translation initiation

Knockdown of the Ribosomal Protein eL29 in Mammalian Cells Leads to Significant Changes in Gene Expression at the Transcription Level

“…Polysome profiles were obtained as described in [34], with minor modifications. For a typical experiment, the HEK293 cell lysate was centrifuged in a 7-47% sucrose gradient at 100,000 g for 4 h at 4 • C using a Beckman SW40 rotor and fractionated with measuring UV absorbance at 260 nm.…”

Ribosomal protein uS3 in cell biology and human disease: Latest insights and prospects

“…In early studies, it has been reported that uS3 in pre-40S subunits is a binding site for assembly factors Ltv1 and Enp1, [70] and that the specific methylation of R64, R65 and R67 in human uS3 is critically required for the protein import into the nucleolus and the 40S subunit assembly. [71] A breakthrough in understanding the role of uS3 in the assembly and maturation of 40S subunits has recently occurred due to detailed biochemical and mutation studies [8,72] and deciphering the structure of pre-40S particles at a sub-atomic level by cryo-electron microscopy [73][74][75][76] (Figure 3). Briefly, the steps of uS3 functioning during the assembly and maturation of 40S subunits can be described as follows: in the cytosol, ribosome-free uS3 exists presumably as a complex containing two uS3 molecules bound to each other via their MDs, and the NTD of one of them is associated with a specific chaperon Yar1, which prevents the protein aggregation.…”

“…A breakthrough in understanding the role of uS3 in the assembly and maturation of 40S subunits has recently occurred due to detailed biochemical and mutation studies [ 8,72 ] and deciphering the structure of pre‐40S particles at a sub‐atomic level by cryo‐electron microscopy [ 73–76 ] (Figure 3). Briefly, the steps of uS3 functioning during the assembly and maturation of 40S subunits can be described as follows: in the cytosol, ribosome‐free uS3 exists presumably as a complex containing two uS3 molecules bound to each other via their MDs, and the NTD of one of them is associated with a specific chaperon Yar1, which prevents the protein aggregation.…”

“…Accordingly, it has been concluded that the distortion of the interaction between 60-GEKG-63 and eIF3j results in a displacement of eIF3j at the decoding site, preventing its dissociation and leaving the 48S PIC unsuitable for joining the 60S subunit. [8] The peptide 55-64 of uS3, comprising 60-GEKG-63, has a unique property to effectively cross-link outside the mRNA binding channel to unstructured RNAs bearing reactive groups, most probably, via the K62. [5,38] The analysis of the data on visualization of spin-labeled RNAs associated with human ribosomes outside the channel by electron paramagnetic resonance [39] has shown that the peptide itself does not bind RNA, assigning a pocket formed by positively charged lysine and arginine residues of uS3 located between K62 and the channel ( Figure 2) as the binding site.…”

“…This role has mainly been judged from various structural data showing uS3 position on the 40S subunit surface relative to the other ribosome components and translational participants in model complexes assembled in vitro. Data on uS3 functioning during the real translation process in vivo and on the contributions of individual parts of the protein to its functions have arisen recently [5][6][7][8] and have not been yet reviewed.…”