Skip to main content
NCBI home page
Genetics logoLink to Genetics
. 2004 Jul;167(3):1305–1315. doi: 10.1534/genetics.103.025379

The GanB Galpha-protein negatively regulates asexual sporulation and plays a positive role in conidial germination in Aspergillus nidulans.

Mi-Hee Chang 1, Keon-Sang Chae 1, Dong-Min Han 1, Kwang-Yeop Jahng 1
PMCID: PMC1470946  PMID: 15280244

Abstract

We isolated the ganB gene encoding the Galpha-protein homolog from Aspergillus nidulans. To investigate the cellular function of GanB, various mutant strains were isolated. Deletion of constitutively inactive ganB mutants showed conidiation and derepressed brlA expression in a submerged culture. Constitutive activation of GanB caused a reduction in hyphal growth and a severe defect in asexual sporulation. We therefore propose that GanB may negatively regulate asexual sporulation through the BrlA pathway. In addition, deletion or constitutive inactivation of GanB reduced germination rate while constitutive activation led to precocious germination. Furthermore, conidia of a constitutively active mutant could germinate even without carbon source. Taken together, these results indicated that GanB plays a positive role during germination, possibly through carbon source sensing, and negatively regulates asexual conidiation in A. nidulans.

Full Text

The Full Text of this article is available as a PDF (323.2 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. 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]
  2. Bohm A., Gaudet R., Sigler P. B. Structural aspects of heterotrimeric G-protein signaling. Curr Opin Biotechnol. 1997 Aug;8(4):480–487. doi: 10.1016/s0958-1669(97)80072-9. [DOI] [PubMed] [Google Scholar]
  3. Brody H., Griffith J., Cuticchia A. J., Arnold J., Timberlake W. E. Chromosome-specific recombinant DNA libraries from the fungus Aspergillus nidulans. Nucleic Acids Res. 1991 Jun 11;19(11):3105–3109. doi: 10.1093/nar/19.11.3105. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Buss J. E., Mumby S. M., Casey P. J., Gilman A. G., Sefton B. M. Myristoylated alpha subunits of guanine nucleotide-binding regulatory proteins. Proc Natl Acad Sci U S A. 1987 Nov;84(21):7493–7497. doi: 10.1073/pnas.84.21.7493. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Bölker M. Sex and crime: heterotrimeric G proteins in fungal mating and pathogenesis. Fungal Genet Biol. 1998 Dec;25(3):143–156. doi: 10.1006/fgbi.1998.1102. [DOI] [PubMed] [Google Scholar]
  6. Choi G. H., Chen B., Nuss D. L. Virus-mediated or transgenic suppression of a G-protein alpha subunit and attenuation of fungal virulence. Proc Natl Acad Sci U S A. 1995 Jan 3;92(1):305–309. doi: 10.1073/pnas.92.1.305. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Coleman D. E., Berghuis A. M., Lee E., Linder M. E., Gilman A. G., Sprang S. R. Structures of active conformations of Gi alpha 1 and the mechanism of GTP hydrolysis. Science. 1994 Sep 2;265(5177):1405–1412. doi: 10.1126/science.8073283. [DOI] [PubMed] [Google Scholar]
  8. Dietzel C., Kurjan J. The yeast SCG1 gene: a G alpha-like protein implicated in the a- and alpha-factor response pathway. Cell. 1987 Sep 25;50(7):1001–1010. doi: 10.1016/0092-8674(87)90166-8. [DOI] [PubMed] [Google Scholar]
  9. Dohlman H. G., Apaniesk D., Chen Y., Song J., Nusskern D. Inhibition of G-protein signaling by dominant gain-of-function mutations in Sst2p, a pheromone desensitization factor in Saccharomyces cerevisiae. Mol Cell Biol. 1995 Jul;15(7):3635–3643. doi: 10.1128/mcb.15.7.3635. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Fillinger Sabine, Chaveroche Marie-Kim, Shimizu Kiminori, Keller Nancy, d'Enfert Christophe. cAMP and ras signalling independently control spore germination in the filamentous fungus Aspergillus nidulans. Mol Microbiol. 2002 May;44(4):1001–1016. doi: 10.1046/j.1365-2958.2002.02933.x. [DOI] [PubMed] [Google Scholar]
  11. Gilman A. G. G proteins: transducers of receptor-generated signals. Annu Rev Biochem. 1987;56:615–649. doi: 10.1146/annurev.bi.56.070187.003151. [DOI] [PubMed] [Google Scholar]
  12. Han K. H., Han K. Y., Yu J. H., Chae K. S., Jahng K. Y., Han D. M. The nsdD gene encodes a putative GATA-type transcription factor necessary for sexual development of Aspergillus nidulans. Mol Microbiol. 2001 Jul;41(2):299–309. doi: 10.1046/j.1365-2958.2001.02472.x. [DOI] [PubMed] [Google Scholar]
  13. Ho S. N., Hunt H. D., Horton R. M., Pullen J. K., Pease L. R. Site-directed mutagenesis by overlap extension using the polymerase chain reaction. Gene. 1989 Apr 15;77(1):51–59. doi: 10.1016/0378-1119(89)90358-2. [DOI] [PubMed] [Google Scholar]
  14. Ivey F. Douglas, Kays Ann M., Borkovich Katherine A. Shared and independent roles for a Galpha(i) protein and adenylyl cyclase in regulating development and stress responses in Neurospora crassa. Eukaryot Cell. 2002 Aug;1(4):634–642. doi: 10.1128/EC.1.4.634-642.2002. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Johnstone I. L., McCabe P. C., Greaves P., Gurr S. J., Cole G. E., Brow M. A., Unkles S. E., Clutterbuck A. J., Kinghorn J. R., Innis M. A. Isolation and characterisation of the crnA-niiA-niaD gene cluster for nitrate assimilation in Aspergillus nidulans. Gene. 1990 Jun 15;90(2):181–192. doi: 10.1016/0378-1119(90)90178-t. [DOI] [PubMed] [Google Scholar]
  16. Kadowaki H., Kadowaki T., Wondisford F. E., Taylor S. I. Use of polymerase chain reaction catalyzed by Taq DNA polymerase for site-specific mutagenesis. Gene. 1989 Mar 15;76(1):161–166. doi: 10.1016/0378-1119(89)90018-8. [DOI] [PubMed] [Google Scholar]
  17. Kays A. M., Rowley P. S., Baasiri R. A., Borkovich K. A. Regulation of conidiation and adenylyl cyclase levels by the Galpha protein GNA-3 in Neurospora crassa. Mol Cell Biol. 2000 Oct;20(20):7693–7705. doi: 10.1128/mcb.20.20.7693-7705.2000. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Kim Hee, Han Kyu, Kim Kyung, Han Dong, Jahng Kwang, Chae Keon. The veA gene activates sexual development in Aspergillus nidulans. Fungal Genet Biol. 2002 Oct;37(1):72–80. doi: 10.1016/s1087-1845(02)00029-4. [DOI] [PubMed] [Google Scholar]
  19. Krüger J., Loubradou G., Regenfelder E., Hartmann A., Kahmann R. Crosstalk between cAMP and pheromone signalling pathways in Ustilago maydis. Mol Gen Genet. 1998 Nov;260(2-3):193–198. doi: 10.1007/s004380050885. [DOI] [PubMed] [Google Scholar]
  20. 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]
  21. Käfer E. Origins of translocations in Aspergillus nidulans. Genetics. 1965 Jul;52(1):217–232. doi: 10.1093/genetics/52.1.217. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Kübler E., Mösch H. U., Rupp S., Lisanti M. P. Gpa2p, a G-protein alpha-subunit, regulates growth and pseudohyphal development in Saccharomyces cerevisiae via a cAMP-dependent mechanism. J Biol Chem. 1997 Aug 15;272(33):20321–20323. doi: 10.1074/jbc.272.33.20321. [DOI] [PubMed] [Google Scholar]
  23. Lee B. N., Adams T. H. Overexpression of flbA, an early regulator of Aspergillus asexual sporulation, leads to activation of brlA and premature initiation of development. Mol Microbiol. 1994 Oct;14(2):323–334. doi: 10.1111/j.1365-2958.1994.tb01293.x. [DOI] [PubMed] [Google Scholar]
  24. Liebmann B., Gattung S., Jahn B., Brakhage A. A. cAMP signaling in Aspergillus fumigatus is involved in the regulation of the virulence gene pksP and in defense against killing by macrophages. Mol Genet Genomics. 2003 May 7;269(3):420–435. doi: 10.1007/s00438-003-0852-0. [DOI] [PubMed] [Google Scholar]
  25. Neves Susana R., Ram Prahlad T., Iyengar Ravi. G protein pathways. Science. 2002 May 31;296(5573):1636–1639. doi: 10.1126/science.1071550. [DOI] [PubMed] [Google Scholar]
  26. Osherov N., May G. S. The molecular mechanisms of conidial germination. FEMS Microbiol Lett. 2001 May 30;199(2):153–160. doi: 10.1111/j.1574-6968.2001.tb10667.x. [DOI] [PubMed] [Google Scholar]
  27. Osherov N., May G. Conidial germination in Aspergillus nidulans requires RAS signaling and protein synthesis. Genetics. 2000 Jun;155(2):647–656. doi: 10.1093/genetics/155.2.647. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. 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]
  29. Parsley Todd B., Segers Gert C., Nuss Donald L., Dawe Angus L. Analysis of altered G-protein subunit accumulation in Cryphonectria parasitica reveals a third Galpha homologue. Curr Genet. 2003 Feb 8;43(1):24–33. doi: 10.1007/s00294-003-0367-6. [DOI] [PubMed] [Google Scholar]
  30. Punt P. J., Strauss J., Smit R., Kinghorn J. R., van den Hondel C. A., Scazzocchio C. The intergenic region between the divergently transcribed niiA and niaD genes of Aspergillus nidulans contains multiple NirA binding sites which act bidirectionally. Mol Cell Biol. 1995 Oct;15(10):5688–5699. doi: 10.1128/mcb.15.10.5688. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. Simon M. I., Strathmann M. P., Gautam N. Diversity of G proteins in signal transduction. Science. 1991 May 10;252(5007):802–808. doi: 10.1126/science.1902986. [DOI] [PubMed] [Google Scholar]
  32. Skiba N. P., Bae H., Hamm H. E. Mapping of effector binding sites of transducin alpha-subunit using G alpha t/G alpha i1 chimeras. J Biol Chem. 1996 Jan 5;271(1):413–424. doi: 10.1074/jbc.271.1.413. [DOI] [PubMed] [Google Scholar]
  33. Som T., Kolaparthi V. S. Developmental decisions in Aspergillus nidulans are modulated by Ras activity. Mol Cell Biol. 1994 Aug;14(8):5333–5348. doi: 10.1128/mcb.14.8.5333. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. Stringer M. A., Dean R. A., Sewall T. C., Timberlake W. E. Rodletless, a new Aspergillus developmental mutant induced by directed gene inactivation. Genes Dev. 1991 Jul;5(7):1161–1171. doi: 10.1101/gad.5.7.1161. [DOI] [PubMed] [Google Scholar]
  35. 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]
  36. Wieser J., Yu J. H., Adams T. H. Dominant mutations affecting both sporulation and sterigmatocystin biosynthesis in Aspergillus nidulans. Curr Genet. 1997 Sep;32(3):218–224. doi: 10.1007/s002940050269. [DOI] [PubMed] [Google Scholar]
  37. Yang Qi, Poole Sheven I., Borkovich Katherine A. A G-protein beta subunit required for sexual and vegetative development and maintenance of normal G alpha protein levels in Neurospora crassa. Eukaryot Cell. 2002 Jun;1(3):378–390. doi: 10.1128/EC.1.3.378-390.2002. [DOI] [PMC free article] [PubMed] [Google Scholar]
  38. 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]
  39. Yu J. H., Rosén S., Adams T. H. Extragenic suppressors of loss-of-function mutations in the aspergillus FlbA regulator of G-protein signaling domain protein. Genetics. 1999 Jan;151(1):97–105. doi: 10.1093/genetics/151.1.97. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Yu J. H., Wieser J., Adams T. H. The Aspergillus FlbA RGS domain protein antagonizes G protein signaling to block proliferation and allow development. EMBO J. 1996 Oct 1;15(19):5184–5190. [PMC free article] [PubMed] [Google Scholar]
  41. Zuber Sophie, Hynes Michael J., Andrianopoulos Alex. G-protein signaling mediates asexual development at 25 degrees C but has no effect on yeast-like growth at 37 degrees C in the dimorphic fungus Penicillium mameffei. Eukaryot Cell. 2002 Jun;1(3):440–447. doi: 10.1128/EC.1.3.440-447.2002. [DOI] [PMC free article] [PubMed] [Google Scholar]
  42. Zuber Sophie, Hynes Michael J., Andrianopoulos Alex. The G-protein alpha-subunit GasC plays a major role in germination in the dimorphic fungus Penicillium marneffei. Genetics. 2003 Jun;164(2):487–499. doi: 10.1093/genetics/164.2.487. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Genetics are provided here courtesy of Oxford University Press

RESOURCES