mTORC1/rpS6 signaling complex that modifies BTB transport function - an in vivo study using the adjudin model.

mTORC1/rpS6 signaling complex that modifies BTB transport function - an in vivo study using the adjudin model. Am J Physiol Endocrinol Metab. 2019 May 21;: Authors: Yan M, Li L, Mao B, Li H, Li SYT, Mruk D, Silvestrini B, Lian Q, Ge R, Cheng CY Abstract Studies have shown that the mTORC1/rpS6 signaling cascade regulates Sertoli cell blood-testis barrier (BTB) dynamics. For instance, specific inhibition of mTORC1 by treating Sertoli cells with rapamycin promotes the Sertoli cell barrier, making it "tighter". However, activation of mTORC1 by overexpressing a full-length rpS6 cDNA clone (i.e., rpS6-WT, wild type) in Sertoli cells promotes BTB remodeling, making the barrier "leaky". Also, there is an increase in rpS6 and p-rpS6 (phosphorylated and activated rpS6) expression at the BTB in testes at stage VIII-IX of the epithelial cycle, and coincides with BTB remodeling to support the transport of preleptotene spermatocytes across the barrier, illustrating rpS6 is a BTB modifying signaling protein. Herein, we used a constitutively active, quadruple phosphomimetic, mutant of rpS6, namely p-rpS6-MT of p-rpS6-S235E/S236E/S240E/S244E wherein Ser (S) was converted to Glu (E) at amino acid residues 235, 236, 240 and 244 from the N-terminus by site-directed mutagenesis, for its overexpression in rat testes in vivo using the Polyplus in vivo jet-PEI transfection reagent with high transfection efficiency. Overexpression of this p-rpS6-MT was capab...
Source: Am J Physiol Endocri... - Category: Endocrinology Authors: Tags: Am J Physiol Endocrinol Metab Source Type: research