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. 1992 Mar 1;89(5):1676–1680. doi: 10.1073/pnas.89.5.1676

A protein required for RNA processing and splicing in Neurospora mitochondria is related to gene products involved in cell cycle protein phosphatase functions.

B Turcq 1, K F Dobinson 1, N Serizawa 1, A M Lambowitz 1
PMCID: PMC48515  PMID: 1311848

Abstract

The Neurospora crassa cyt-4 mutants have pleiotropic defects in mitochondrial RNA splicing, 5' and 3' end processing, and RNA turnover. Here, we show that the cyt-4+ gene encodes a 120-kDa protein with significant similarity to the SSD1/SRK1 protein of Saccharomyces cerevisiae and the DIS3 protein of Schizosaccharomyces pombe, which have been implicated in protein phosphatase functions that regulate cell cycle and mitotic chromosome segregation. The CYT-4 protein is present in mitochondria and is truncated or deficient in two cyt-4 mutants. Assuming that the CYT-4 protein functions in a manner similar to the SSD1/SRK1 and DIS3 proteins, we infer that the mitochondrial RNA splicing and processing reactions defective in the cyt-4 mutants are regulated by protein phosphorylation and that the defects in the cyt-4 mutants result from failure to normally regulate this process. Our results provide evidence that RNA splicing and processing reactions may be regulated by protein phosphorylation.

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Selected References

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  1. Akins R. A., Lambowitz A. M. A protein required for splicing group I introns in Neurospora mitochondria is mitochondrial tyrosyl-tRNA synthetase or a derivative thereof. Cell. 1987 Jul 31;50(3):331–345. doi: 10.1016/0092-8674(87)90488-0. [DOI] [PubMed] [Google Scholar]
  2. Akins R. A., Lambowitz A. M. General method for cloning Neurospora crassa nuclear genes by complementation of mutants. Mol Cell Biol. 1985 Sep;5(9):2272–2278. doi: 10.1128/mcb.5.9.2272. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Arndt K. T., Styles C. A., Fink G. R. A suppressor of a HIS4 transcriptional defect encodes a protein with homology to the catalytic subunit of protein phosphatases. Cell. 1989 Feb 24;56(4):527–537. doi: 10.1016/0092-8674(89)90576-x. [DOI] [PubMed] [Google Scholar]
  4. Bertrand H., Bridge P., Collins R. A., Garriga G., Lambowitz A. M. RNA splicing in Neurospora mitochondria. Characterization of new nuclear mutants with defects in splicing the mitochondrial large rRNA. Cell. 1982 Jun;29(2):517–526. doi: 10.1016/0092-8674(82)90168-4. [DOI] [PubMed] [Google Scholar]
  5. Cherniack A. D., Garriga G., Kittle J. D., Jr, Akins R. A., Lambowitz A. M. Function of Neurospora mitochondrial tyrosyl-tRNA synthetase in RNA splicing requires an idiosyncratic domain not found in other synthetases. Cell. 1990 Aug 24;62(4):745–755. doi: 10.1016/0092-8674(90)90119-y. [DOI] [PubMed] [Google Scholar]
  6. Collins R. A., Lambowitz A. M. RNA splicing in Neurospora mitochondria. Defective splicing of mitochondrial mRNA precursors in the nuclear mutant cyt18-1. J Mol Biol. 1985 Aug 5;184(3):413–428. doi: 10.1016/0022-2836(85)90291-8. [DOI] [PubMed] [Google Scholar]
  7. Dobinson K. F., Henderson M., Kelley R. L., Collins R. A., Lambowitz A. M. Mutations in nuclear gene cyt-4 of Neurospora crassa result in pleiotropic defects in processing and splicing of mitochondrial RNAs. Genetics. 1989 Sep;123(1):97–108. doi: 10.1093/genetics/123.1.97. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Garriga G., Bertrand H., Lambowitz A. M. RNA splicing in Neurospora mitochondria: nuclear mutants defective in both splicing and 3' end synthesis of the large rRNA. Cell. 1984 Mar;36(3):623–634. doi: 10.1016/0092-8674(84)90342-8. [DOI] [PubMed] [Google Scholar]
  9. Garriga G., Lambowitz A. M. Protein-dependent splicing of a group I intron in ribonucleoprotein particles and soluble fractions. Cell. 1986 Aug 29;46(5):669–680. doi: 10.1016/0092-8674(86)90342-9. [DOI] [PubMed] [Google Scholar]
  10. Germann U. A., Müller G., Hunziker P. E., Lerch K. Characterization of two allelic forms of Neurospora crassa laccase. Amino- and carboxyl-terminal processing of a precursor. J Biol Chem. 1988 Jan 15;263(2):885–896. [PubMed] [Google Scholar]
  11. Henikoff S. Unidirectional digestion with exonuclease III creates targeted breakpoints for DNA sequencing. Gene. 1984 Jun;28(3):351–359. doi: 10.1016/0378-1119(84)90153-7. [DOI] [PubMed] [Google Scholar]
  12. Higgins D. G., Sharp P. M. Fast and sensitive multiple sequence alignments on a microcomputer. Comput Appl Biosci. 1989 Apr;5(2):151–153. doi: 10.1093/bioinformatics/5.2.151. [DOI] [PubMed] [Google Scholar]
  13. Kittle J. D., Jr, Mohr G., Gianelos J. A., Wang H., Lambowitz A. M. The Neurospora mitochondrial tyrosyl-tRNA synthetase is sufficient for group I intron splicing in vitro and uses the carboxy-terminal tRNA-binding domain along with other regions. Genes Dev. 1991 Jun;5(6):1009–1021. doi: 10.1101/gad.5.6.1009. [DOI] [PubMed] [Google Scholar]
  14. Koerner T. J., Hill J. E., Myers A. M., Tzagoloff A. High-expression vectors with multiple cloning sites for construction of trpE fusion genes: pATH vectors. Methods Enzymol. 1991;194:477–490. doi: 10.1016/0076-6879(91)94036-c. [DOI] [PubMed] [Google Scholar]
  15. Kraft R., Tardiff J., Krauter K. S., Leinwand L. A. Using mini-prep plasmid DNA for sequencing double stranded templates with Sequenase. Biotechniques. 1988 Jun;6(6):544-6, 549. [PubMed] [Google Scholar]
  16. Kubelik A. R., Turcq B., Lambowitz A. M. The Neurospora crassa cyt-20 gene encodes cytosolic and mitochondrial valyl-tRNA synthetases and may have a second function in addition to protein synthesis. Mol Cell Biol. 1991 Aug;11(8):4022–4035. doi: 10.1128/mcb.11.8.4022. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Kuiper M. T., Sabourin J. R., Lambowitz A. M. Identification of the reverse transcriptase encoded by the Mauriceville and Varkud mitochondrial plasmids of Neurospora. J Biol Chem. 1990 Apr 25;265(12):6936–6943. [PubMed] [Google Scholar]
  18. Majumder A. L., Akins R. A., Wilkinson J. G., Kelley R. L., Snook A. J., Lambowitz A. M. Involvement of tyrosyl-tRNA synthetase in splicing of group I introns in Neurospora crassa mitochondria: biochemical and immunochemical analyses of splicing activity. Mol Cell Biol. 1989 May;9(5):2089–2104. doi: 10.1128/mcb.9.5.2089. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Mannella C. A., Collins R. A., Green M. R., Lambowitz A. M. Defective splicing of mitochondrial rRNA in cytochrome-deficient nuclear mutants of Neurospora crassa. Proc Natl Acad Sci U S A. 1979 Jun;76(6):2635–2639. doi: 10.1073/pnas.76.6.2635. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Ohkura H., Adachi Y., Kinoshita N., Niwa O., Toda T., Yanagida M. Cold-sensitive and caffeine-supersensitive mutants of the Schizosaccharomyces pombe dis genes implicated in sister chromatid separation during mitosis. EMBO J. 1988 May;7(5):1465–1473. doi: 10.1002/j.1460-2075.1988.tb02964.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Ohkura H., Kinoshita N., Miyatani S., Toda T., Yanagida M. The fission yeast dis2+ gene required for chromosome disjoining encodes one of two putative type 1 protein phosphatases. Cell. 1989 Jun 16;57(6):997–1007. doi: 10.1016/0092-8674(89)90338-3. [DOI] [PubMed] [Google Scholar]
  22. Orbach M. J., Porro E. B., Yanofsky C. Cloning and characterization of the gene for beta-tubulin from a benomyl-resistant mutant of Neurospora crassa and its use as a dominant selectable marker. Mol Cell Biol. 1986 Jul;6(7):2452–2461. doi: 10.1128/mcb.6.7.2452. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Pearson W. R., Lipman D. J. Improved tools for biological sequence comparison. Proc Natl Acad Sci U S A. 1988 Apr;85(8):2444–2448. doi: 10.1073/pnas.85.8.2444. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Perkins D. D., Radford A., Newmeyer D., Björkman M. Chromosomal loci of Neurospora crassa. Microbiol Rev. 1982 Dec;46(4):426–570. doi: 10.1128/mr.46.4.426-570.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Pittenger T. H., West D. J. Isolation and characterization of temperature-sensitive respiratory mutants of Neurospora crassa. Genetics. 1979 Nov;93(3):539–555. doi: 10.1093/genetics/93.3.539. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. 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]
  27. Sutton A., Immanuel D., Arndt K. T. The SIT4 protein phosphatase functions in late G1 for progression into S phase. Mol Cell Biol. 1991 Apr;11(4):2133–2148. doi: 10.1128/mcb.11.4.2133. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Vollmer S. J., Yanofsky C. Efficient cloning of genes of Neurospora crassa. Proc Natl Acad Sci U S A. 1986 Jul;83(13):4869–4873. doi: 10.1073/pnas.83.13.4869. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Wilson R. B., Brenner A. A., White T. B., Engler M. J., Gaughran J. P., Tatchell K. The Saccharomyces cerevisiae SRK1 gene, a suppressor of bcy1 and ins1, may be involved in protein phosphatase function. Mol Cell Biol. 1991 Jun;11(6):3369–3373. doi: 10.1128/mcb.11.6.3369. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. von Heijne G., Steppuhn J., Herrmann R. G. Domain structure of mitochondrial and chloroplast targeting peptides. Eur J Biochem. 1989 Apr 1;180(3):535–545. doi: 10.1111/j.1432-1033.1989.tb14679.x. [DOI] [PubMed] [Google Scholar]

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