UCSF

MESH1 is the metazoan homolog of bacterial SpoT, the main phosphatase that dephosphorylates and degrades (p)ppGpp, the alarmone involved in the bacterial stringent response. The functional role of MESH1 in human cells is unknown. To define the global transcriptional response to MESH1 knockdown, we employed microarrays to perform transcriptome analysis of H1975 when the MESH1 was knocked down using three independent siRNAs targeting MESH1. The changes of each gene were derived by zero-transformation, followed by filtering to derive the genes affected by MESH1 knockdown. These datasets showed the transcriptional features of the mammalian stringent response and identified a prominent TAZ repression. Thus, we performed a second experiment to determine the contribution of TAZ repression to the transcriptional response of MESH1 knockdown by comparing the effects of MESH1-knockdown gene signatures in H1975 cells transduced with control or constitutive active TAZ (TAZS89A). The transcriptional response of these two cells to MESH1 was derived by zero transformation, followed by the effects of TAZ restoration to define the contribution of TAZ repression to the transcriptome features of human stringent response. The transcriptome data will be useful for the mechanistic understanding of the functional role of MESH1 in human cancer cells.