A motif within a complex promoter from the oomycete Phytophthora infestans determines transcription during an intermediate stage of sporulation.
Sporulation in Phytophthora infestans is associated with a major remodeling of the transcriptome. To better understand promoter structure and how sporulation-specific expression is determined in this organism, the Pks1 gene was analyzed. Pks1 encodes a protein kinase that is induced at an intermediate stage of sporulation, prior to sporangium maturation. Major and minor transcription start sites mapped throughout the promoter, which contains many T-rich stretches and Inr-like elements. Within the T-rich region are several motifs which bound nuclear proteins in EMSA. Tests of modified promoters in transformants implicated a CCGTTG located 110-nt upstream of the transcription start point as a major regulator of sporulation-specific transcription. The motif also bound a sporulation-specific nuclear protein complex. A bioinformatics analysis indicated that the motif is highly over-represented within co-expressed promoters, in which it predominantly resides 100-300-nt upstream of transcription start sites. Other sequences, such as a CATTTGTT motif, also bound nuclear proteins but did not play an essential role in spore-specific expression.
Xiang
Qijun
Q
Department of Plant Pathology and Microbiology, University of California, Riverside, 92521, USA.
Kim
Kyoung Su
KS
Roy
Sourav
S
Judelson
Howard S
HS
D019677:Artificial Gene Fusion; D001483:Base Sequence; D001665:Binding Sites; D004271:DNA, Fungal / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D017930:Genes, Reporter; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D055750:Phytophthora infestans / Q000502:physiology*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013172:Spores, Fungal / Q000254:growth & development*; D024363:Transcription Initiation Site; D014158:Transcription, Genetic
D004271:DNA, Fungal; D005656:Fungal Proteins; D011494:Protein Kinases; D005966:Glucuronidase