Homogalacturonan synthesis in <i>Arabidopsis thaliana</i> requires a Golgi‐localized protein with a putative methyltransferase domain

Mouille, Grégory; Ralet, Marie-Christine; Cavelier, Céline; Eland, Cathlene; Effroy, Delphine; Hématy, Kian; McCartney, Lesley; Truong, Hoai Nam; Gaudon, Virginie; Thibault, Jean-François; Marchant, Alan; Höfte, Monica

doi:10.1111/j.1365-313x.2007.03086.x

Cited by 216 publications

(313 citation statements)

References 47 publications

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“…Consistently, many members of the Domain of Unknown Function248 putative pectin methyltransferase family were detected and quantified (14 of a total of 35 members) as well as cotton (Gossypium hirsutum) Golgi-related2 (At3g49720) belonging to another putative homogalacturonan methyltransferase family (Mouille et al, 2007;Held et al, 2011;Miao et al, 2011). In sum, they constitute 10% of the quantified Golgi proteome.…”

Section: Quantities Of the Cell Wall Synthesis Machineries In The Golmentioning

confidence: 72%

Label-Free Protein Quantification for Plant Golgi Protein Localization and Abundance

et al. 2014

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The proteomic composition of the Arabidopsis (Arabidopsis thaliana) Golgi apparatus is currently reasonably well documented; however, little is known about the relative abundances between different proteins within this compartment. Accurate quantitative information of Golgi resident proteins is of great importance: it facilitates a better understanding of the biochemical processes that take place within this organelle, especially those of different polysaccharide synthesis pathways. Golgi resident proteins are challenging to quantify because the abundance of this organelle is relatively low within the cell. In this study, an organelle fractionation approach targeting the Golgi apparatus was combined with a label-free quantitative mass spectrometry (dataindependent acquisition method using ion mobility separation known as LC-IMS-MS E [or HDMS E ]) to simultaneously localize proteins to the Golgi apparatus and assess their relative quantity. In total, 102 Golgi-localized proteins were quantified. These data show that organelle fractionation in conjunction with label-free quantitative mass spectrometry is a powerful and relatively simple tool to access protein organelle localization and their relative abundances. The findings presented open a unique view on the organization of the plant Golgi apparatus, leading toward unique hypotheses centered on the biochemical processes of this organelle.

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Section: Quantities Of the Cell Wall Synthesis Machineries In The Golmentioning

confidence: 72%

Label-Free Protein Quantification for Plant Golgi Protein Localization and Abundance

et al. 2014

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“…The regulation of the DM of HG has been implicated in many aspects of plant development (Wolf et al, 2009a), including cell adhesion (Tieman and Handa, 1994;Wen et al, 1999;Mollet et al, 2000;Bouton et al, 2002;Mouille et al, 2007;Durand et al, 2009), adventitious rooting (Guénin et al, 2011), primordia emergence at the shoot apical meristem (Peaucelle et al, 2008(Peaucelle et al, , 2011, fruit ripening (Brummell and Harpster, 2001;Phan et al, 2007), and plant defense (Bethke et al, 2014). Although data have shown an important role for Figure 5.…”

Section: Discussionmentioning

confidence: 99%

PECTIN METHYLESTERASE48 Is Involved in Arabidopsis Pollen Grain Germination

et al. 2014

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Germination of pollen grains is a crucial step in plant reproduction. However, the molecular mechanisms involved remain unclear. We investigated the role of PECTIN METHYLESTERASE48 (PME48), an enzyme implicated in the remodeling of pectins in Arabidopsis (Arabidopsis thaliana) pollen. A combination of functional genomics, gene expression, in vivo and in vitro pollen germination, immunolabeling, and biochemical analyses was used on wild-type and Atpme48 mutant plants. We showed that AtPME48 is specifically expressed in the male gametophyte and is the second most expressed PME in dry and imbibed pollen grains. Pollen grains from homozygous mutant lines displayed a significant delay in imbibition and germination in vitro and in vivo. Moreover, numerous pollen grains showed two tips emerging instead of one in the wild type. Immunolabeling and Fourier transform infrared analyses showed that the degree of methylesterification of the homogalacturonan was higher in pme482/2 pollen grains. In contrast, the PME activity was lower in pme482/2, partly due to a reduction of PME48 activity revealed by zymogram. Interestingly, the wild-type phenotype was restored in pme482/2 with the optimum germination medium supplemented with 2.5 mM calcium chloride, suggesting that in the wild-type pollen, the weakly methylesterified homogalacturonan is a source of Ca 2+ necessary for pollen germination. Although pollen-specific PMEs are traditionally associated with pollen tube elongation, this study provides strong evidence that PME48 impacts the mechanical properties of the intine wall during maturation of the pollen grain, which, in turn, influences pollen grain germination.

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“…Although none of the candidate GMTs has yet been functionally tested, it is likely that some of them are involved in the methylation of HGA in the lumen of the Golgi. Recently, Mouille et al (2007) showed that the QUA2 locus from Arabidopsis (Arabidopsis thaliana) encodes a putative methyltransferase that is Golgi localized. A QUA2 mutant exhibited a decrease in HGA, and the corresponding gene is coexpressed with GAUT1, a galacturonosyltransferase involved in HGA biosynthesis (Sterling et al, 2006).…”

Section: Discussionmentioning

confidence: 99%

The Import of S-Adenosylmethionine into the Golgi Apparatus Is Required for the Methylation of Homogalacturonan

Ibar

Orellana

2007

Plant Physiology

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S-adenosylmethionine (SAM) is the substrate used in the methylation of homogalacturonan (HGA) in the Golgi apparatus. SAM is synthesized in the cytosol, but it is not currently known how it is then transported into the Golgi. In this study, we find that HGA methyltransferase is present in Golgi-enriched fractions and that its catalytic domain faces the lumen of this organelle. This suggests that SAM must be imported into the Golgi. We performed uptake experiments using [methyl-14 C]SAM and found that SAM is incorporated into the Golgi vesicles, resulting in the methylation of polymers that are sensitive to pectinase and pectin methylesterase but not to proteases. To avoid detecting the transfer reaction, we also used [carboxyl-14 C]SAM, the uptake of which into Golgi vesicles was found to be sensitive to temperature, detergents, and osmotic changes, and to be saturable with a K m of 33 mM. Double-label uptake experiments using [methyl-3 H]SAM and [carboxyl-14 C]SAM also revealed a time-dependent increase in the 3 H to 14 C ratio, suggesting that upon transfer of the methyl group, the resulting S-adenosylhomocysteine is not accumulated in the Golgi. SAM incorporation was also found to be inhibited by S-adenosylhomocysteine, whereas UDP-GalA, UDP-GlcA, and acetyl-CoA had no effect. DIDS, a compound that inhibits nucleotide sugar transporters, also had little effect upon SAM incorporation. Interestingly, the combination of UDP-GalA 1 acetyl-CoA or UDP-GlcA 1 acetyl-CoA produced a slight increase in the uptake of SAM. These results support the idea that a SAM transporter is required for HGA biosynthesis.

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Homogalacturonan synthesis in Arabidopsis thaliana requires a Golgi‐localized protein with a putative methyltransferase domain

Cited by 216 publications

References 47 publications

Label-Free Protein Quantification for Plant Golgi Protein Localization and Abundance

Label-Free Protein Quantification for Plant Golgi Protein Localization and Abundance

PECTIN METHYLESTERASE48 Is Involved in Arabidopsis Pollen Grain Germination

The Import of S-Adenosylmethionine into the Golgi Apparatus Is Required for the Methylation of Homogalacturonan

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