<em>Xenopus laevis</em> as a Model to Identify Translation Impairment

Abstract

Protein synthesis is a fundamental process to gene expression impacting diverse biological processes notably adaptation to environmental conditions. The initiation step, which involves the assembly of the ribosomal subunits at the mRNA initiation codon, involved initiation factor including eIF4G1. Defects in this rate limiting step of translation are linked to diverse disorders. To study the potential consequences of such deregulations, Xenopus laevis oocytes constitute an attractive model with high degrees of conservation of essential cellular and molecular mechanisms with human. In addition, during meiotic maturation, oocytes are transcriptionally repressed and all necessary proteins are translated from preexisting, maternally derived mRNAs. This inexpensive model enables exogenous mRNA to become perfectly integrated with an effective translation. Here is described a protocol for assessing translation with a factor of interest (here eIF4G1) using stored maternal mRNA that are the first to be polyadenylated and translated during oocyte maturation as a physiological readout. At first, mRNA synthetized by in vitro transcription of plasmids of interest (here eIF4G1) are injected in oocytes and kinetics of oocyte maturation by Germinal Vesicle Breakdown detection is determined. The studied maternal mRNA target is the serine/threonine-protein-kinase mos. Its polyadenylation and its subsequent translation are investigated together with the expression and phosphorylation of proteins of the mos signaling cascade involved in oocyte maturation. Variations of the current protocol to put forward translational defects are also proposed to emphasize its general applicability. In light of emerging evidence that aberrant protein synthesis may be involved in the pathogenesis of neurological disorders, such a model provides the opportunity to easily assess this impairment and identify new targets.

Differentially expressed IGF2BP2 in ovarian disorders: strongly associates with alternative splicing regulation in human granulosa cells

“…Similarly, the enriched KEGG pathways were related with protein processing in endoplasmic reticulum, legionellosis, mTOR signaling pathway, small cell lung cancer, RNA transport and spliceosome, among others. Hence, based on our functional analysis, it can be concluded that IGF2BP2 in uences the expression of certain genes by regulating alternative splicing in KGN cells and that some of these genes included RPL26, HSPA8, RPL17, EIF4G1, PSMC5 and U2AF1 which were associated with ovarian diseases in previous studies [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44].…”