Localization and Post-translational Processing of the Wound-induced Leucine Aminopeptidase Proteins of Tomato

Gu, Yong–Qiang; Chao, Wun S.; Walling, Linda L.

doi:10.1074/jbc.271.42.25880

Cited by 47 publications

(85 citation statements)

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“…The LapN cDNA probe detected three EcoRI fragments in tomato genomic DNA. The 10-and 3-kb fragments represented the LapA1 and LapA2 genes, respectively (Gu et al, 1996a;Chao et al, 2000). The LapN gene was located on a 7-kb EcoRI fragment, and singlecopy reconstructions indicated that LapN was present once in the haploid tomato genome.…”

Section: Isolation and Characterization Of Lapnmentioning

confidence: 99%

“…6). This protein was similar in size (577 residues) and had 77% amino acid identity (87% similarity) with the wound-induced LAP-A1 and LAP-A2 preproteins of tomato (Gu et al, 1996a). Because the mature LAP-A and LAP-N proteins detected in 2D-PAGE immunoblots were 55 kD, this 5-kD N-terminal extension must be efficiently processed in vivo.…”

Section: Rnas and Proteinsmentioning

confidence: 99%

“…A, Four GST-LapN fusion genes containing domains A, B, D, and F were constructed and overexpressed in E. coli. Black bars, LapA1-coding regions in the 1.9-kb full-length LapA1 cDNA clone pBLapA1 (Gu et al, 1996a), the partial LapA1 cDNA clone pDR57 corresponding to LapA1 nucleotides 325 to 1,843 (Pautot et al, 1993), and the GSTLapA fusion constructs. The glutathione-S-transferase (GST)-LAP-A fusion proteins contained the following amino acid residues: A (residues 123-194), B (residues 195-233), D (residues 290-424), and F (residues 534-571).…”

Section: Lap-n and Lap-a Protein Accumulation In Vegetative And Repromentioning

confidence: 99%

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Isolation and Characterization of the Neutral Leucine Aminopeptidase (LapN) of Tomato

Park

Walling

2003

Plant Physiology

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Tomatoes (Lycopersicon esculentum) express two forms of leucine aminopeptidase (LAP-A and LAP-N) and two LAP-like proteins. The relatedness of LAP-N and LAP-A was determined using affinity-purified antibodies to four LAP-A protein domains. Antibodies to epitopes in the most N-terminal region were able to discriminate between LAP-A and LAP-N, whereas antibodies recognizing central and COOH-terminal regions recognized both LAP polypeptides. Two-dimensional immunoblots showed that LAP-N and the LAP-like proteins were detected in all vegetative (leaves, stems, roots, and cotyledons) and reproductive (pistils, sepals, petals, stamens, and floral buds) organs examined, whereas LAP-A exhibited a distinct expression program. LapN was a single-copy gene encoding a rare-class transcript. A full-length LapN cDNA clone was isolated, and the deduced sequence had 77% peptide sequence identity with the wound-induced LAP-A. Leucyl aminopeptidases (LAPs; EC 3.4.11.1) are members of the M17 family of peptidases (Barrett et al., 1998). LAPs are ubiquitous being found in animals, plants, and prokaryotic cells. These hexameric metallopeptidases catalyze the release of the N-terminal residues from protein, peptide, fluorometric, and chromogenic substrates. The best characterized LAPs are from Bos taurus, Escherichia coli and tomato (Lycopersicon esculentum). X-ray crystal structures of the bovine and E. coli LAPs have provided insight into the LAP catalytic mechanism (Kim and Lipscomb, 1994;Sträter and Lipscomb, 1995;Sträter et al., 1999a). The roles of selected residues of the E. coli and tomato LAPs in chromogenic or peptide substrate catalysis, respectively, have been tested by site-directed mutagenesis (Sträter et al., 1999b;Gu and Walling, 2002).In most plants, three classes of LAP-related polypeptides are detected using a tomato LAP antiserum, including the 66-and 77-kD LAP-like proteins and the 55-kD neutral LAP (LAP-N; Chao et al., 2000). Only in a subset of the Solanaceae is a second 55-kD LAP species (LAP-A) detected (Hildmann et al., 1992;Gu et al., 1996b;Chao et al., 2000). In tomato, LAP-A protomers have an acidic pI and are encoded by two genes (LapA1 and LapA2), which are expressed during floral and fruit development. The LapA genes are not expressed in foliage from healthy plants (Chao et al., 1999). However, LapA RNAs, proteins, and activities accumulate locally and systemically in leaves after wounding, Pseudomonas syringae pv. tomato and Phytophthora parasitica infection, and caterpillar feeding (Pautot et al., 1993(Pautot et al., , 2001Gu et al., 1996b;Chao et al., 1999;Jwa and Walling, 2001). The activation of LapA gene expression by jasmonic acid (JA), abscisic acid, the phytotoxin coronatine (a JA mimic), and suppression of LapA by salicylic acid is consistent with the regulation of the tomato LapA genes by the wound octadecanoid pathway (Chao et al., 1999). LapA genes also respond to signals generated during water deficit and salinity stress (Chao et al., 1999). The potato (Solanum tuberosum) Lap RNAs also ac...

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Section: Isolation and Characterization Of Lapnmentioning

confidence: 99%

Section: Rnas and Proteinsmentioning

confidence: 99%

Section: Lap-n and Lap-a Protein Accumulation In Vegetative And Repromentioning

confidence: 99%

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Isolation and Characterization of the Neutral Leucine Aminopeptidase (LapN) of Tomato

Park

Walling

2003

Plant Physiology

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“…Whereas the plant 26S proteasome and several exopeptidases that release single amino acids have been described biochemically (e.g. Callis, 1995;Gu et al, 1996), the endo/exopeptidases that fulfill these intermediate roles are not well known.In animals, tripeptidyl peptidase (TPP)II is an intermediate exopeptidase thought to be necessary for efficient protein turnover (EC 3.4.14.10;Tomkinson, 1999). This aminopeptidase was first identified as a Ser 2 These authors contributed equally to the paper.…”

mentioning

confidence: 99%

mentioning

confidence: 99%

Tripeptidyl Peptidase II. An Oligomeric Protease Complex from Arabidopsis

et al. 2005

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The breakdown of most nuclear and cytoplasmic proteins involves their partial cleavage by the 26S proteasome followed by further disassembly to free amino acids by the combined action of endo-and exopeptidases. In animals, one important intermediate exopeptidase is tripeptidyl peptidase (TPP)II, which digests peptide products of the 26S proteasome and other endopeptidases into tripeptides. Here, we describe the purification and characterization of TPPII from Arabidopsis (Arabidopsis thaliana). Like its animal counterparts, Arabidopsis TPPII exists as a soluble, approximately 5-to 9-MD complex. Two related species of 153 and 142 kD are present in the purified preparations that are derived from a single TPP2 gene. Sequencing by Edman degradation of the intact polypeptides and mass spectrometry of proteolytic fragments demonstrated that the 142-kD form mainly differs from the 153-kD form by a truncation at the C-terminal end. This serine protease is a member of the subtilisin superfamily and is sensitive to the inhibitors alanine-alanine-phenylalanine-chloromethylketone and butabindide, which are diagnostic for the TPPII subfamily. The Arabidopsis TPP2 gene is widely expressed in many tissue types with related genes evident in other plant genomes. Whereas the 26S proteasome is essential, TPPII appears not as important for plant physiology. An Arabidopsis T-DNA mutant defective in TPP2 expression displays no phenotypic abnormalities and is not hypersensitive to either amino acid analogs or the 26S proteasome inhibitor MG132. As a consequence, plants likely contain other intermediate exopeptidases that assist in amino acid recycling.Proteolysis serves a variety of essential functions, including the elimination of misfolded or damaged proteins, the precise removal of regulatory proteins, and the maintenance of free amino acid pools needed for continual protein synthesis (Vierstra, 1996;Tomkinson, 1999). To facilitate this breakdown, plants and animals have evolved several proteolytic mechanisms for each subcellular compartment. In the vacuole/lysosome, proteins are catabolized by a variety of proteases and peptidases following their delivery to this hydrolytic compartment via endocytic and autophagic mechanisms (Thompson and Vierstra, 2005). For nuclear and cytoplasmic proteins, as well as abnormal polypeptides transported in a retrograde fashion from the endoplasmic reticulum to the cytoplasm, a major route involves ubiquitin (Ub) and the 26S proteasome (Smalle and Vierstra, 2004). Here, proteins destined for degradation are selectively tagged by the covalent attachment of multiple Ubs.These ubiquitinated proteins are then recognized and cleaved into smaller fragments by the 26S proteasome, a self-compartmentalized ATP-dependent protease complex with broad substrate and cleavage specificity.Products of the 26S proteasome are predominantly peptides 6 to 12 amino acids in length (Wenzel et al., 1994;Kisselev et al., 1999;Voges et al., 1999). Complete recycling requires further cleavage of these peptides by intermediate...

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Proteomic analysis of tobacco mosaic virus-infected tomato (Lycopersicon esculentum M.) fruits and detection of viral coat protein

2006

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Tobacco mosaic virus (TMV) is a widespread plant virus from the genus Tobamovirus that affects tobacco and tomato plants causing a pathology characterised by cell breakage and disorganisation in plant leaves and fruits. In this study we undertook a proteomic approach to investigate the molecular and biochemical mechanisms potentially involved in tomato fruit defence against the viral infection. The comparison of 2-D gels from control and TMV-infected but asymptomatic tomato fruits revealed changes in several proteins. The differential expression of peptidases, endoglucanase, chitinase and proteins participating in the ascorbate-glutathione cycle in infected fruits suggests that pathogenesis-related proteins and antioxidant enzymes may play a role in the protection against TMV infection. TMV coat protein appeared as a prominent spot in 2-D gels from TMV-infected asymptomatic fruits. A Triton X-114 phase-partitioning step of tomato protein extracts favoured the solubilisation of TMV coat protein and the enrichment of two aminopeptidases not present in control fruits. PMF and MS/MS data of the 2-D gel-isolated TMV coat protein is proposed as a powerful analysis method for the simultaneous tobamovirus detection, species determination and strain differentiation in virus-infected fruit commodities.

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Localization and Post-translational Processing of the Wound-induced Leucine Aminopeptidase Proteins of Tomato

Cited by 47 publications

References 50 publications

Isolation and Characterization of the Neutral Leucine Aminopeptidase (LapN) of Tomato

Isolation and Characterization of the Neutral Leucine Aminopeptidase (LapN) of Tomato

Tripeptidyl Peptidase II. An Oligomeric Protease Complex from Arabidopsis

Proteomic analysis of tobacco mosaic virus-infected tomato (Lycopersicon esculentum M.) fruits and detection of viral coat protein

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