Abstract
A putative citrus vacuolar processing thiolprotease cDNA (Cit-vac) was isolated from a cDNA library of Citrus fruits (Citrus sinensis L. Osbeck var Washington navel). The cDNA is 58 and 57% identical with vacuolar processing seed proteases from castor bean and soybean, respectively. The Citvac sequence shows a typical signal peptide for entering into the endoplasmic reticulum and two glycosylation signals. Using an in vitro transcription-translation system, we show that the Citvac precursor is able to enter a microsomal fraction and to undergo proteolytic processing and glycosylation. Transcript levels for the Citvac are developmentally regulated in the flavedo (outer colored part of the fruit peel) and increase during fruit ripening and in the flower during opening. Exogenous treatment with ethylene induces Citvac mRNA expression in both fruits and leaves. Citvac is encoded by one or two genes in the Citrus genome. The possible role of the Citvac gene product during fruit ripening and other ethylene-mediated processes is discussed.
Full Text
The Full Text of this article is available as a PDF (2.2 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bond J. S., Butler P. E. Intracellular proteases. Annu Rev Biochem. 1987;56:333–364. doi: 10.1146/annurev.bi.56.070187.002001. [DOI] [PubMed] [Google Scholar]
- Cohen L. W., Coghlan V. M., Dihel L. C. Cloning and sequencing of papain-encoding cDNA. Gene. 1986;48(2-3):219–227. doi: 10.1016/0378-1119(86)90080-6. [DOI] [PubMed] [Google Scholar]
- Dellapenna D., Bennett A. B. In vitro synthesis and processing of tomato fruit polygalacturonase. Plant Physiol. 1988 Apr;86(4):1057–1063. doi: 10.1104/pp.86.4.1057. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hara-Nishimura I., Inoue K., Nishimura M. A unique vacuolar processing enzyme responsible for conversion of several proprotein precursors into the mature forms. FEBS Lett. 1991 Dec 2;294(1-2):89–93. doi: 10.1016/0014-5793(91)81349-d. [DOI] [PubMed] [Google Scholar]
- Hara-Nishimura I., Nishimura M. Proglobulin processing enzyme in vacuoles isolated from developing pumpkin cotyledons. Plant Physiol. 1987 Oct;85(2):440–445. doi: 10.1104/pp.85.2.440. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hara-Nishimura I., Takeuchi Y., Nishimura M. Molecular characterization of a vacuolar processing enzyme related to a putative cysteine proteinase of Schistosoma mansoni. Plant Cell. 1993 Nov;5(11):1651–1659. doi: 10.1105/tpc.5.11.1651. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jones J. D., Dunsmuir P., Bedbrook J. High level expression of introduced chimaeric genes in regenerated transformed plants. EMBO J. 1985 Oct;4(10):2411–2418. doi: 10.1002/j.1460-2075.1985.tb03949.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Klinkert M. Q., Felleisen R., Link G., Ruppel A., Beck E. Primary structures of Sm31/32 diagnostic proteins of Schistosoma mansoni and their identification as proteases. Mol Biochem Parasitol. 1989 Mar 1;33(2):113–122. doi: 10.1016/0166-6851(89)90025-x. [DOI] [PubMed] [Google Scholar]
- Mauch F., Staehelin L. A. Functional Implications of the Subcellular Localization of Ethylene-Induced Chitinase and [beta]-1,3-Glucanase in Bean Leaves. Plant Cell. 1989 Apr;1(4):447–457. doi: 10.1105/tpc.1.4.447. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rasmussen G. K. Cellulase Activity, Endogenous Abscisic Acid, and Ethylene in Four Citrus Cultivars during Maturation. Plant Physiol. 1975 Dec;56(6):765–767. doi: 10.1104/pp.56.6.765. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Riov J., Monselise S. P., Kahan R. S. Ethylene-controlled Induction of Phenylalanine Ammonia-lyase in Citrus Fruit Peel. Plant Physiol. 1969 May;44(5):631–635. doi: 10.1104/pp.44.5.631. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Scott M. P., Jung R., Muntz K., Nielsen N. C. A protease responsible for post-translational cleavage of a conserved Asn-Gly linkage in glycinin, the major seed storage protein of soybean. Proc Natl Acad Sci U S A. 1992 Jan 15;89(2):658–662. doi: 10.1073/pnas.89.2.658. [DOI] [PMC free article] [PubMed] [Google Scholar]