Occurrence of Low Molecular Weight and High Cysteine Containing Albumin Storage Proteins in Oilseeds of Diverse Species

Youle, Richard J.; Huang, Anthony H. C.

doi:10.1002/j.1537-2197.1981.tb06354.x

Cited by 135 publications

(63 citation statements)

References 20 publications

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“…As expected, the napin-type albumins (Figures 7B and 7D) were identified in the 2S fractions of the gradient, and the legumintype globulin ␣-and ␤-chains ( Figures 7B and 7C) represented the predominant polypeptides in the 12S fractions. Interestingly, in contrast to the seed protein sedimentation profiles of many other plant species but similar to those of Brassica spp (Youle and Huang, 1981), only very minor amounts of polypeptides were observed in the 7S fractions of the gradient. The ‫-52ف‬ to 30-kD polypeptides detected in these fractions ( Figure 7B, fractions 13 to 18; see also Figure 9A, lane 1) likely represent the previously identified processed N-and C-terminal chains of vicilin-like proteins (Gruis et al, 2002), which are minor storage proteins in Arabidopsis seeds (F. Gruis, unpublished data).…”

Section: Assembly Of Seed Proteins In Vpe Mutantsmentioning

confidence: 66%

Storage Protein Accumulation in the Absence of the Vacuolar Processing Enzyme Family of Cysteine Proteases[W]

2004

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The role(s) of specific proteases in seed protein processing is only vaguely understood; indeed, the overall role of processing in stable protein deposition has been the subject of more speculation than direct investigation. Seed-type members of the vacuolar processing enzyme (VPE) family were hypothesized to perform a unique function in seed protein processing, but we demonstrated previously that Asn-specific protein processing in developing Arabidopsis seeds occurs independently of this VPE activity. Here, we describe the unexpected expression of vegetative-type VPEs in developing seeds and test the role(s) of all VPEs in seed storage protein accumulation by systematically stacking knockout mutant alleles of all four members ( ␣ VPE , ␤ VPE , ␥ VPE , and ␦ VPE ) of the VPE gene family in Arabidopsis. The complete removal of VPE function in the ␣ vpe ␤ vpe ␥ vpe ␦ vpe quadruple mutant resulted in a total shift of storage protein accumulation from wild-type processed polypeptides to a finite number of prominent alternatively processed polypeptides cleaved at sites other than the conserved Asn residues targeted by VPE. Although alternatively proteolyzed legumin-type globulin polypeptides largely accumulated as intrasubunit disulfide-linked polypeptides with apparent molecular masses similar to those of VPE-processed legumin polypeptides, they showed markedly altered solubility and protein assembly characteristics. Instead of forming 11S hexamers, alternatively processed legumin polypeptides were deposited primarily as 9S complexes. However, despite the impact on seed protein processing, plants devoid of all known functional VPE genes appeared unchanged with regard to protein content in mature seeds, relative mobilization rates of protein reserves during germination, and vegetative growth. These findings indicate that VPE-mediated Asn-specific proteolytic processing, and the physiochemical property changes attributed to this specific processing step, are not required for the successful deposition and mobilization of seed storage protein in the protein storage vacuoles of Arabidopsis seeds.

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Section: Assembly Of Seed Proteins In Vpe Mutantsmentioning

confidence: 66%

Storage Protein Accumulation in the Absence of the Vacuolar Processing Enzyme Family of Cysteine Proteases[W]

2004

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“…The 2S albumins are small water soluble proteins found in a variety of plant species (Youle and Huang, 1981). Phylogenetic relationships have been established among 2S albumins found in different crucifers (Raynal et al, 1991).…”

Section: Introductionmentioning

confidence: 99%

A cotyledon regulatory region is responsible for the different spatial expression patterns of Arabidopsis 2S albumin genes

Conceição

Krebbers²

1994

The Plant Journal

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SummaryThe 2S albumin genes of Arabidopsis thallana are a model system to study gene expression during late embryogeneeis. The at2Sl gene has previously been shown to be expressed essentially in the embryo axis, unlike at2S2, which is expressed throughout the embryo. Hybrid promoter constructs between at2Sl and at2S2 were Introduced Into Arabidopsla end used to identify a cotyledon regulatory region necessary for 2S albumin expression in palisade paranchyma and specific epidermal cells. Other promoter sequences flanking this tisaue-speclflc promoter element were shown to control mRNA exprosalon levels independently of the mRNA distribution throughout the embryos. Certain hybrid promoters resulted in the alteration of the time course of expression in cotyledons. Differential expression of 2S albumin genes is dlscusaed in terms of layered cellular organization and mitotic activity throughout the embryo.

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“…Relatively little is known about the expression of 2S albumins in transgenic plants, although they constitute the most abundant class of seed storage proteins in many dicot plants (41). Also referred to as 1.7S albumins or napin-like proteins (8,41), they are water-soluble seed storage proteins, present in multiple isoforms and composed of two polypeptide chains of 8 to 12 and 3 to 5 kD, linked by disulfide bridges (2,16,23).…”

mentioning

confidence: 99%

“…Also referred to as 1.7S albumins or napin-like proteins (8,41), they are water-soluble seed storage proteins, present in multiple isoforms and composed of two polypeptide chains of 8 to 12 and 3 to 5 kD, linked by disulfide bridges (2,16,23). 2S albumin genes are encoded by multigene families (36) and are of particular interest because cDNA (1,8,13) and gene cloning experiments (23,30) have shown that the protein is formed from large precursors which undergo extensive proteolytic processing, including signal peptide cleavage, removal of an additional amino-terminal fragment as well as an internal segment, and elimination of a few carboxy-terminal residues (8,16).…”

mentioning

confidence: 99%

Expression and Processing of an Arabidopsis 2S Albumin in Transgenic Tobacco

Clercq

Vandewiele²,

Rycke³

et al. 1990

Plant Physiol.

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2S albumin seed storage proteins undergo a complex series of posttranslational proteolytic cleavages. In order to determine if this process is correctly carried out in transgenic plants, the gene AT2S1 encoding an Arabidopsis thaliana 2S albumin isoform has been expressed in transgenic tobacco. Initial experiments using a reporter gene demonstrated that the AT2S1 promoter directs seed specific expression in both transgenic tobacco and Brassica napus plants. The entire AT2S1 gene was then transferred into tobacco plants, where it showed a tissue specific and developmentally regulated expression. Arabidopsis 2S albumin accumulates up to 0.1% of the total high-salt extractable seed protein. Protein sequencing demonstrated that the amino termini of the two Arabidopsis 2S albumin subunits were correctly processed, suggesting that the protease(s) necessary for posttranslational processing of 2S albumin precursors may display common specificities among different dicot plant species. Immunocytochemical studies showed that the Arabidopsis 2S albumin is localized in the protein body matrix of tobacco endosperm and embryo. Correct processing and targeting of the 2S albumin in transgenic plants suggests that modified versions could be expressed, allowing the study of 2S albumin processing and in particular the possible roles of the processed fragments in protein stability and/or targeting.

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Occurrence of Low Molecular Weight and High Cysteine Containing Albumin Storage Proteins in Oilseeds of Diverse Species

Cited by 135 publications

References 20 publications

Storage Protein Accumulation in the Absence of the Vacuolar Processing Enzyme Family of Cysteine Proteases[W]

Storage Protein Accumulation in the Absence of the Vacuolar Processing Enzyme Family of Cysteine Proteases[W]

A cotyledon regulatory region is responsible for the different spatial expression patterns of Arabidopsis 2S albumin genes

Expression and Processing of an Arabidopsis 2S Albumin in Transgenic Tobacco

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