Regulation of LRG1 expression by RNA ‐binding protein Puf5 in the budding yeast cell wall integrity pathway

Puf5 functions in the yeast cell wall integrity pathway by regulatingLRG1 expression in a deadenylase ‐independent manner, and Puf6 is involved in the Ccr4‐ and Puf5‐mediated regulation of cell growth through association with Rpl43. AbstractThe PUF RNA ‐binding protein Puf5 is involved in regulation of the cell wall integrity (CWI) pathway in yeast. Puf5 negatively regulates expression ofLRG1 mRNA, encoding for a GTPase ‐activating protein for Rho1 small GTPase. Here, we further analyzed the effect of Puf5 onLRG1 expression, together with Ccr4 and Pop2 deadenylases, Dhh1 decapping activator, and other PUF proteins. We found that the growth defect ofpuf5 ∆ mutant was enhanced byccr4 ∆ mutation, which was partially suppressed byLRG1deletion. Consistently, Lrg1 protein level was much more up ‐regulated inccr4Δpuf5Δ double mutant than in each single mutant. Interestingly,LRG1 poly(A) tail length was longer inccr4 ∆ mutant but not inpuf5 ∆ mutant. Thus, Puf5 regulatesLRG1 expression independently from Ccr4, although Puf5 recruits the Ccr4 ‐Not deadenylase complex for mRNA destabilization. Unexpectedly,puf6Δ mutation suppressed the growth defect caused byccr4Δpuf5 ∆ mutation. Loss of Rpl43a and Rpl43b ribosomal proteins, the previously identified Puf6 interactors, also suppressed the growth defect ofccr4Δpuf5Δ mutant. Our results suggest that Puf5 functions in the CWI pathway by regulatingLRG1expression in a deadenylase ‐independent manner, and that...

Source: Genes to Cells - October 31, 2018 Category: Genetics & Stem Cells Authors: Nguyen Thi Minh Viet, Duong Long Duy, Kazuhiro Saito, Kaoru Irie, Yasuyuki Suda, Tomoaki Mizuno, Kenji Irie Tags: ORIGINAL ARTICLE Source Type: research