CrebA regulates secretory activity in the Drosophila salivary gland and epidermis.
Understanding how organs acquire the capacity to perform their respective functions is important for both cell and developmental biology. Here, we have examined the role of early-expressed transcription factors in activating genes crucial for secretory function in the Drosophila salivary gland. We show that expression of genes encoding proteins required for ER targeting and translocation, and proteins that mediate transport between the ER and Golgi is very high in the early salivary gland. This high level expression requires two early salivary gland transcription factors; CrebA is required throughout embryogenesis and Fkh is required only during late embryonic stages. As Fkh is required to maintain late CrebA expression in the salivary gland, Fkh probably works through CrebA to affect secretory pathway gene expression. In support of these regulatory interactions, we show that CrebA is important for elevated secretion in the salivary gland. Additionally, CrebA is required for the expression of the secretory pathway genes in the embryonic epidermis, where CrebA had previously been shown to be essential for cuticle development. We show that zygotic mutations in several individual secretory pathway genes result in larval cuticle phenotypes nearly identical to those of CrebA mutants. Thus, CrebA activity is linked to secretory function in multiple tissues.
Abrams
Elliott W
EW
Department of Cell Biology, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205, USA.
Andrew
Deborah J
DJ
D000818:Animals; D001483:Base Sequence; D051699:Cyclic AMP Response Element-Binding Protein A; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000196:embryology* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D004817:Epidermis / Q000196:embryology / Q000378:metabolism*; D051858:Forkhead Transcription Factors; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D007814:Larva / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D008840:Microfilament Proteins; D009154:Mutation / Q000235:genetics; D009687:Nuclear Proteins; D021381:Protein Transport; D012469:Salivary Glands / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics; D015854:Up-Regulation / Q000235:genetics
C073555:CrebA protein, Drosophila; D051699:Cyclic AMP Response Element-Binding Protein A; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D051858:Forkhead Transcription Factors; D008840:Microfilament Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; C084628:f protein, Drosophila; C512745:fkh protein, Drosophila