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. 1997 Oct;17(10):6191–6201. doi: 10.1128/mcb.17.10.6191

Aspergillus asexual reproduction and sexual reproduction are differentially affected by transcriptional and translational mechanisms regulating stunted gene expression.

J Wu 1, B L Miller 1
PMCID: PMC232470  PMID: 9315680

Abstract

The Stunted protein (StuAp) is a member of a family of transcription factors that regulate fungal development and cell cycle progression. Regulated stuA gene expression is required for correct cell pattern formation during asexual reproduction (conidiation) and for initiation of the sexual reproductive cycle in Aspergillus nidulans. Transcriptional initiation from two different promoters yields overlapping mRNAs (stuA alpha and stuAbeta) that upon translation yield the same protein. Here we show that multiple regulatory mechanisms interact to control (i) developmental competence-dependent expression of both transcripts and (ii) induction-dependent expression of stuA alpha, but not stuAbeta, by the conidiation-specific Bristle (BrlAp) transcriptional activator. Quantitative levels of both mRNAs are further modulated by (i) an activator(s) located at a far-upstream upstream activation sequence, (ii) feedback regulation by StuAp, and (iii) positive translational regulation that requires the peptide product of a micro-open reading frame unique to the stuA alpha mRNA 5' untranslated region. Gradients in stuA alpha expression were most important for correct cell and tissue type development. Threshold requirements were as follows: metula-phialide differentiation < ascosporogenesis < cleistothecial shell-Hülle cell differentiation. Altered stuA expression affected conidiophore morphology and conidial yields quantitatively but did not alter the temporal development of cell types or conidiophore density. By contrast, the sexual cycle showed both temporal delay and quantitative reduction in the number of cleistothecial initials but normal morphogenesis of tissue types.

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Selected References

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  1. Abastado J. P., Miller P. F., Jackson B. M., Hinnebusch A. G. Suppression of ribosomal reinitiation at upstream open reading frames in amino acid-starved cells forms the basis for GCN4 translational control. Mol Cell Biol. 1991 Jan;11(1):486–496. doi: 10.1128/mcb.11.1.486. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Adams T. H., Boylan M. T., Timberlake W. E. brlA is necessary and sufficient to direct conidiophore development in Aspergillus nidulans. Cell. 1988 Jul 29;54(3):353–362. doi: 10.1016/0092-8674(88)90198-5. [DOI] [PubMed] [Google Scholar]
  3. Adams T. H., Timberlake W. E. Developmental repression of growth and gene expression in Aspergillus. Proc Natl Acad Sci U S A. 1990 Jul;87(14):5405–5409. doi: 10.1073/pnas.87.14.5405. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Adams T. H., Timberlake W. E. Upstream elements repress premature expression of an Aspergillus developmental regulatory gene. Mol Cell Biol. 1990 Sep;10(9):4912–4919. doi: 10.1128/mcb.10.9.4912. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Aguirre J. Spatial and temporal controls of the Aspergillus brlA developmental regulatory gene. Mol Microbiol. 1993 Apr;8(2):211–218. doi: 10.1111/j.1365-2958.1993.tb01565.x. [DOI] [PubMed] [Google Scholar]
  6. Andrews B. J., Herskowitz I. The yeast SWI4 protein contains a motif present in developmental regulators and is part of a complex involved in cell-cycle-dependent transcription. Nature. 1989 Dec 14;342(6251):830–833. doi: 10.1038/342830a0. [DOI] [PubMed] [Google Scholar]
  7. Andrianopoulos A., Timberlake W. E. The Aspergillus nidulans abaA gene encodes a transcriptional activator that acts as a genetic switch to control development. Mol Cell Biol. 1994 Apr;14(4):2503–2515. doi: 10.1128/mcb.14.4.2503. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Aramayo R., Peleg Y., Addison R., Metzenberg R. Asm-1+, a Neurospora crassa gene related to transcriptional regulators of fungal development. Genetics. 1996 Nov;144(3):991–1003. doi: 10.1093/genetics/144.3.991. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Aramayo R., Timberlake W. E. The Aspergillus nidulans yA gene is regulated by abaA. EMBO J. 1993 May;12(5):2039–2048. doi: 10.1002/j.1460-2075.1993.tb05853.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Arnosti D. N., Barolo S., Levine M., Small S. The eve stripe 2 enhancer employs multiple modes of transcriptional synergy. Development. 1996 Jan;122(1):205–214. doi: 10.1242/dev.122.1.205. [DOI] [PubMed] [Google Scholar]
  11. Axelrod D. E., Gealt M., Pastushok M. Gene control of developmental competence in Aspergillus nidulans. Dev Biol. 1973 Sep;34(1):9–15. doi: 10.1016/0012-1606(73)90335-7. [DOI] [PubMed] [Google Scholar]
  12. Boylan M. T., Mirabito P. M., Willett C. E., Zimmerman C. R., Timberlake W. E. Isolation and physical characterization of three essential conidiation genes from Aspergillus nidulans. Mol Cell Biol. 1987 Sep;7(9):3113–3118. doi: 10.1128/mcb.7.9.3113. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Busby T. M., Miller K. Y., Miller B. L. Suppression and enhancement of the Aspergillus nidulans medusa mutation by altered dosage of the bristle and stunted genes. Genetics. 1996 May;143(1):155–163. doi: 10.1093/genetics/143.1.155. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Caligiuri M., Beach D. Sct1 functions in partnership with Cdc10 in a transcription complex that activates cell cycle START and inhibits differentiation. Cell. 1993 Feb 26;72(4):607–619. doi: 10.1016/0092-8674(93)90079-6. [DOI] [PubMed] [Google Scholar]
  15. Casadaban M. J., Martinez-Arias A., Shapira S. K., Chou J. Beta-galactosidase gene fusions for analyzing gene expression in escherichia coli and yeast. Methods Enzymol. 1983;100:293–308. doi: 10.1016/0076-6879(83)00063-4. [DOI] [PubMed] [Google Scholar]
  16. Champe S. P., Nagle D. L., Yager L. N. Sexual sporulation. Prog Ind Microbiol. 1994;29:429–454. [PubMed] [Google Scholar]
  17. Chang Y. C., Timberlake W. E. Identification of Aspergillus brlA response elements (BREs) by genetic selection in yeast. Genetics. 1993 Jan;133(1):29–38. doi: 10.1093/genetics/133.1.29. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Chen E. Y., Seeburg P. H. Supercoil sequencing: a fast and simple method for sequencing plasmid DNA. DNA. 1985 Apr;4(2):165–170. doi: 10.1089/dna.1985.4.165. [DOI] [PubMed] [Google Scholar]
  19. Clutterbuck A. J. A mutational analysis of conidial development in Aspergillus nidulans. Genetics. 1969 Oct;63(2):317–327. doi: 10.1093/genetics/63.2.317. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Courey A. J., Huang J. D. The establishment and interpretation of transcription factor gradients in the Drosophila embryo. Biochim Biophys Acta. 1995 Mar 14;1261(1):1–18. doi: 10.1016/0167-4781(94)00234-t. [DOI] [PubMed] [Google Scholar]
  21. Covitz P. A., Herskowitz I., Mitchell A. P. The yeast RME1 gene encodes a putative zinc finger protein that is directly repressed by a1-alpha 2. Genes Dev. 1991 Nov;5(11):1982–1989. doi: 10.1101/gad.5.11.1982. [DOI] [PubMed] [Google Scholar]
  22. Covitz P. A., Mitchell A. P. Repression by the yeast meiotic inhibitor RME1. Genes Dev. 1993 Aug;7(8):1598–1608. doi: 10.1101/gad.7.8.1598. [DOI] [PubMed] [Google Scholar]
  23. Dever T. E., Feng L., Wek R. C., Cigan A. M., Donahue T. F., Hinnebusch A. G. Phosphorylation of initiation factor 2 alpha by protein kinase GCN2 mediates gene-specific translational control of GCN4 in yeast. Cell. 1992 Feb 7;68(3):585–596. doi: 10.1016/0092-8674(92)90193-g. [DOI] [PubMed] [Google Scholar]
  24. Doonan J. H. Cell division in Aspergillus. J Cell Sci. 1992 Nov;103(Pt 3):599–611. doi: 10.1242/jcs.103.3.599. [DOI] [PubMed] [Google Scholar]
  25. Frigerio G., Burri M., Bopp D., Baumgartner S., Noll M. Structure of the segmentation gene paired and the Drosophila PRD gene set as part of a gene network. Cell. 1986 Dec 5;47(5):735–746. doi: 10.1016/0092-8674(86)90516-7. [DOI] [PubMed] [Google Scholar]
  26. Fujioka M., Jaynes J. B., Goto T. Early even-skipped stripes act as morphogenetic gradients at the single cell level to establish engrailed expression. Development. 1995 Dec;121(12):4371–4382. doi: 10.1242/dev.121.12.4371. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Gimeno C. J., Fink G. R. Induction of pseudohyphal growth by overexpression of PHD1, a Saccharomyces cerevisiae gene related to transcriptional regulators of fungal development. Mol Cell Biol. 1994 Mar;14(3):2100–2112. doi: 10.1128/mcb.14.3.2100. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Gómez-Pardo E., Peñalva M. A. The upstream region of the IPNS gene determines expression during secondary metabolism in Aspergillus nidulans. Gene. 1990 Apr 30;89(1):109–115. doi: 10.1016/0378-1119(90)90212-a. [DOI] [PubMed] [Google Scholar]
  29. Hamer J. E., Timberlake W. E. Functional organization of the Aspergillus nidulans trpC promoter. Mol Cell Biol. 1987 Jul;7(7):2352–2359. doi: 10.1128/mcb.7.7.2352. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Han S., Navarro J., Greve R. A., Adams T. H. Translational repression of brlA expression prevents premature development in Aspergillus. EMBO J. 1993 Jun;12(6):2449–2457. doi: 10.1002/j.1460-2075.1993.tb05899.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. Hermann T. E., Kurtz M. B., Champe S. P. Laccase localized in hulle cells and cleistothecial primordia of Aspergillus nidulans. J Bacteriol. 1983 May;154(2):955–964. doi: 10.1128/jb.154.2.955-964.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Kirk K. E., Morris N. R. The tubB alpha-tubulin gene is essential for sexual development in Aspergillus nidulans. Genes Dev. 1991 Nov;5(11):2014–2023. doi: 10.1101/gad.5.11.2014. [DOI] [PubMed] [Google Scholar]
  33. Koch C., Moll T., Neuberg M., Ahorn H., Nasmyth K. A role for the transcription factors Mbp1 and Swi4 in progression from G1 to S phase. Science. 1993 Sep 17;261(5128):1551–1557. doi: 10.1126/science.8372350. [DOI] [PubMed] [Google Scholar]
  34. Kron S. J., Styles C. A., Fink G. R. Symmetric cell division in pseudohyphae of the yeast Saccharomyces cerevisiae. Mol Biol Cell. 1994 Sep;5(9):1003–1022. doi: 10.1091/mbc.5.9.1003. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Käfer E. Meiotic and mitotic recombination in Aspergillus and its chromosomal aberrations. Adv Genet. 1977;19:33–131. doi: 10.1016/s0065-2660(08)60245-x. [DOI] [PubMed] [Google Scholar]
  36. Lee B. N., Adams T. H. The Aspergillus nidulans fluG gene is required for production of an extracellular developmental signal and is related to prokaryotic glutamine synthetase I. Genes Dev. 1994 Mar 15;8(6):641–651. doi: 10.1101/gad.8.6.641. [DOI] [PubMed] [Google Scholar]
  37. Lovett P. S., Rogers E. J. Ribosome regulation by the nascent peptide. Microbiol Rev. 1996 Jun;60(2):366–385. doi: 10.1128/mr.60.2.366-385.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
  38. Lowndes N. F., McInerny C. J., Johnson A. L., Fantes P. A., Johnston L. H. Control of DNA synthesis genes in fission yeast by the cell-cycle gene cdc10+. Nature. 1992 Jan 30;355(6359):449–453. doi: 10.1038/355449a0. [DOI] [PubMed] [Google Scholar]
  39. Luo Z., Sachs M. S. Role of an upstream open reading frame in mediating arginine-specific translational control in Neurospora crassa. J Bacteriol. 1996 Apr;178(8):2172–2177. doi: 10.1128/jb.178.8.2172-2177.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Messenguy F., Feller A., Crabeel M., Piérard A. Control-mechanisms acting at the transcriptional and post-transcriptional levels are involved in the synthesis of the arginine pathway carbamoylphosphate synthase of yeast. EMBO J. 1983;2(8):1249–1254. doi: 10.1002/j.1460-2075.1983.tb01577.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  41. Miller B. L., Miller K. Y., Roberti K. A., Timberlake W. E. Position-dependent and -independent mechanisms regulate cell-specific expression of the SpoC1 gene cluster of Aspergillus nidulans. Mol Cell Biol. 1987 Jan;7(1):427–434. doi: 10.1128/mcb.7.1.427. [DOI] [PMC free article] [PubMed] [Google Scholar]
  42. Miller B. L., Miller K. Y., Timberlake W. E. Direct and indirect gene replacements in Aspergillus nidulans. Mol Cell Biol. 1985 Jul;5(7):1714–1721. doi: 10.1128/mcb.5.7.1714. [DOI] [PMC free article] [PubMed] [Google Scholar]
  43. Miller K. Y., Toennis T. M., Adams T. H., Miller B. L. Isolation and transcriptional characterization of a morphological modifier: the Aspergillus nidulans stunted (stuA) gene. Mol Gen Genet. 1991 Jun;227(2):285–292. doi: 10.1007/BF00259682. [DOI] [PubMed] [Google Scholar]
  44. Miller K. Y., Wu J., Miller B. L. StuA is required for cell pattern formation in Aspergillus. Genes Dev. 1992 Sep;6(9):1770–1782. doi: 10.1101/gad.6.9.1770. [DOI] [PubMed] [Google Scholar]
  45. Mirabito P. M., Adams T. H., Timberlake W. E. Interactions of three sequentially expressed genes control temporal and spatial specificity in Aspergillus development. Cell. 1989 Jun 2;57(5):859–868. doi: 10.1016/0092-8674(89)90800-3. [DOI] [PubMed] [Google Scholar]
  46. Miyamoto M., Tanaka K., Okayama H. res2+, a new member of the cdc10+/SWI4 family, controls the 'start' of mitotic and meiotic cycles in fission yeast. EMBO J. 1994 Apr 15;13(8):1873–1880. doi: 10.1002/j.1460-2075.1994.tb06456.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  47. Mooney J. L., Yager L. N. Light is required for conidiation in Aspergillus nidulans. Genes Dev. 1990 Sep;4(9):1473–1482. doi: 10.1101/gad.4.9.1473. [DOI] [PubMed] [Google Scholar]
  48. Mueller P. P., Hinnebusch A. G. Multiple upstream AUG codons mediate translational control of GCN4. Cell. 1986 Apr 25;45(2):201–207. doi: 10.1016/0092-8674(86)90384-3. [DOI] [PubMed] [Google Scholar]
  49. PONTECORVO G., ROPER J. A., HEMMONS L. M., MACDONALD K. D., BUFTON A. W. J. The genetics of Aspergillus nidulans. Adv Genet. 1953;5:141–238. doi: 10.1016/s0065-2660(08)60408-3. [DOI] [PubMed] [Google Scholar]
  50. Pankratz M. J., Jäckle H. Making stripes in the Drosophila embryo. Trends Genet. 1990 Sep;6(9):287–292. doi: 10.1016/0168-9525(90)90234-w. [DOI] [PubMed] [Google Scholar]
  51. Prade R. A., Timberlake W. E. The Aspergillus nidulans brlA regulatory locus consists of overlapping transcription units that are individually required for conidiophore development. EMBO J. 1993 Jun;12(6):2439–2447. doi: 10.1002/j.1460-2075.1993.tb05898.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  52. Primig M., Sockanathan S., Auer H., Nasmyth K. Anatomy of a transcription factor important for the start of the cell cycle in Saccharomyces cerevisiae. Nature. 1992 Aug 13;358(6387):593–597. doi: 10.1038/358593a0. [DOI] [PubMed] [Google Scholar]
  53. Salser S. J., Kenyon C. Patterning C. elegans: homeotic cluster genes, cell fates and cell migrations. Trends Genet. 1994 May;10(5):159–164. doi: 10.1016/0168-9525(94)90092-2. [DOI] [PubMed] [Google Scholar]
  54. Sanger F., Nicklen S., Coulson A. R. DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci U S A. 1977 Dec;74(12):5463–5467. doi: 10.1073/pnas.74.12.5463. [DOI] [PMC free article] [PubMed] [Google Scholar]
  55. Skromne I., Sánchez O., Aguirre J. Starvation stress modulates the expression of the Aspergillus nidulans brlA regulatory gene. Microbiology. 1995 Jan;141(Pt 1):21–28. doi: 10.1099/00221287-141-1-21. [DOI] [PubMed] [Google Scholar]
  56. Southern E. M. Detection of specific sequences among DNA fragments separated by gel electrophoresis. J Mol Biol. 1975 Nov 5;98(3):503–517. doi: 10.1016/s0022-2836(75)80083-0. [DOI] [PubMed] [Google Scholar]
  57. Struhl G., Johnston P., Lawrence P. A. Control of Drosophila body pattern by the hunchback morphogen gradient. Cell. 1992 Apr 17;69(2):237–249. doi: 10.1016/0092-8674(92)90405-2. [DOI] [PubMed] [Google Scholar]
  58. Struhl G., Struhl K., Macdonald P. M. The gradient morphogen bicoid is a concentration-dependent transcriptional activator. Cell. 1989 Jun 30;57(7):1259–1273. doi: 10.1016/0092-8674(89)90062-7. [DOI] [PubMed] [Google Scholar]
  59. Tanaka K., Okazaki K., Okazaki N., Ueda T., Sugiyama A., Nojima H., Okayama H. A new cdc gene required for S phase entry of Schizosaccharomyces pombe encodes a protein similar to the cdc 10+ and SWI4 gene products. EMBO J. 1992 Dec;11(13):4923–4932. doi: 10.1002/j.1460-2075.1992.tb05599.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  60. Timberlake W. E. Molecular genetics of Aspergillus development. Annu Rev Genet. 1990;24:5–36. doi: 10.1146/annurev.ge.24.120190.000253. [DOI] [PubMed] [Google Scholar]
  61. Timberlake W. E. Translational Triggering and Feedback Fixation in the Control of Fungal Development. Plant Cell. 1993 Oct;5(10):1453–1460. doi: 10.1105/tpc.5.10.1453. [DOI] [PMC free article] [PubMed] [Google Scholar]
  62. Tzamarias D., Roussou I., Thireos G. Coupling of GCN4 mRNA translational activation with decreased rates of polypeptide chain initiation. Cell. 1989 Jun 16;57(6):947–954. doi: 10.1016/0092-8674(89)90333-4. [DOI] [PubMed] [Google Scholar]
  63. Ward M. P., Gimeno C. J., Fink G. R., Garrett S. SOK2 may regulate cyclic AMP-dependent protein kinase-stimulated growth and pseudohyphal development by repressing transcription. Mol Cell Biol. 1995 Dec;15(12):6854–6863. doi: 10.1128/mcb.15.12.6854. [DOI] [PMC free article] [PubMed] [Google Scholar]
  64. Yager L. N., Kurtz M. B., Champe S. P. Temperature-shift analysis of conidial development in Aspergillus nidulans. Dev Biol. 1982 Sep;93(1):92–103. doi: 10.1016/0012-1606(82)90242-1. [DOI] [PubMed] [Google Scholar]
  65. Yelton M. M., Hamer J. E., Timberlake W. E. Transformation of Aspergillus nidulans by using a trpC plasmid. Proc Natl Acad Sci U S A. 1984 Mar;81(5):1470–1474. doi: 10.1073/pnas.81.5.1470. [DOI] [PMC free article] [PubMed] [Google Scholar]
  66. Zhu Y., Takeda T., Nasmyth K., Jones N. pct1+, which encodes a new DNA-binding partner of p85cdc10, is required for meiosis in the fission yeast Schizosaccharomyces pombe. Genes Dev. 1994 Apr 15;8(8):885–898. doi: 10.1101/gad.8.8.885. [DOI] [PubMed] [Google Scholar]
  67. van Gorcom R. F., Pouwels P. H., Goosen T., Visser J., van den Broek H. W., Hamer J. E., Timberlake W. E., van den Hondel C. A. Expression of an Escherichia coli beta-galactosidase fusion gene in Aspergillus nidulans. Gene. 1985;40(1):99–106. doi: 10.1016/0378-1119(85)90028-9. [DOI] [PubMed] [Google Scholar]

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