TY - JOUR AU - Jiao, Jian AU - Wang, Shuai AU - Tian, Hui AU - Xu, Xinxin AU - Zhang, Yuhong AU - Liu, Bo AU - Zhang, Wei PY - 2020 DA - 2020/02/25 TI - Decreased expression of LRA4, a key gene involved in rhamnose metabolism, caused up-regulated expression of the genes in this pathway and autophagy in Pichia pastoris JO - AMB Express SP - 37 VL - 10 IS - 1 AB - In a previous study, we developed Pichia pastoris GS115m, an engineered strain with decreased expression of one key gene, LRA4, in rhamnose metabolism. P. pastoris GS115m/LacB was subsequently constructed via introducing a β-galactosidase gene, LacB, under the control of rhamnose-inducible PLRA3 into P. pastoris GS115m. P. pastoris GS115m/LacB greatly improved recombinant protein production relative to the parental strain (P. pastoris GS115/LacB). In the present study, transcriptomes of P. pastoris GS115m/LacB and P. pastoris GS115/LacB grown in YPR medium were analyzed. P. pastoris GS115m/LacB was found to suffer from the mild carbon source starvation. To attenuate the starvation stress, P. pastoris GS115m/LacB attempted to enhance rhamnose metabolism by elevating the transcription levels of rhamnose-utilization genes LRA1-3 and RhaR. The transcription level of LacB under the control of PLRA3 thereby increased, resulting in the improved production of recombinant protein in P. pastoris GS115m/LacB. It was also revealed that P. pastoris GS115m/LacB cells coped with carbon starvation mostly via autophagy. SN - 2191-0855 UR - https://doi.org/10.1186/s13568-020-00971-2 DO - 10.1186/s13568-020-00971-2 ID - Jiao2020 ER -