Systematic analysis of lysine 2-hydroxyisobutyrylation posttranslational modification in wheat leaves

Abstract

Lysine 2-hydroxyisobutyrylation (Khib) is a recently discovered post-translational modification (PTM) showing diverse biological functions and effects in living organisms. However, the study of Khib in plant species is still relatively limited. Wheat (Triticum aestivum L.) is a global important cereal plant. In this study, the systematic Khib analysis was performed in wheat leave tissues. A total of 3004 Khib sites in 1104 proteins were repeatedly identified. Structure characterization of these Khib peptides revealed 12 conserved sequence motifs. Function classification and enrichment analysis indicated these Khib proteins showed a wide function and pathway distribution, of which ribosome activity, protein biosynthesis and photosynthesis were the preferred biological processes. Subcellular location predication indicated chloroplast was the dominant subcellular compartment where Khib was distributed. There may be some crosstalks among Khib, lysine acetylation and lysine succinylation modification because some proteins and sites were modified by all these three acylations. The present study demonstrated the critical role of Khib in wheat biological and physiology, which has expanded the scope of Khib in plant species. Our study is an available resource and reference of Khib function demonstration and structure characterization in cereal plant, as well as in plant kingdom.

Proteomic analysis of protein lysine 2-hydroxyisobutyrylation (Khib) in soybean leaves

“…Surprisingly, several proteins contained more than 28 K hib sites, such as lipoxygenase (accession number: A0A0R0G554, 28 sites), Glutamine amidotransferase type-2 domain-containing protein (accession number: A0A368UIE9, 30 sites) and an uncharacterized protein (accession number: I1MRV6, 29 sites) (Table S 1 ). The distribution of K hib -modified peptide lengths and the number of K hib sites contained in individual proteins in soybean were similar to those found in wheat [ 21 , 22 ] and rice [ 20 ]. The identification of such a large number of K hib -modified sites and proteins in soybean not only indicates that K hib modification is an abundant and complex PTM, but also indicates that this modification may have a very important role in regulating protein functions in soybean.…”

“…Since then, this protein modification has been found in various organisms, including animals, microorganisms and plants. In plants, proteome-wide K hib modifications have been profiled in Arabidopsis siliques [ 7 ], rhubarb [ 23 ], wheat [ 5 , 22 ], rice [ 20 , 29 ], etc. Soybean is an important economic crop grown worldwide [ 25 ].…”

“…Taken together, the enrichment analysis results suggest that K hib -modified proteins related to biosynthesis and metabolism are extremely important for the physiological functions of soybean leaves. Notably, K hib -modified proteins involved in metabolism and biosynthesis were also found to be significantly enriched in other plants, such as rice [ 19 , 20 ], wheat [ 5 , 22 ], and rhubarb [ 23 ]. The enrichment of K hib -modified proteins associated with central carbon metabolism and biosynthesis found in plants for which global analyses of K hib modifications have been performed to date suggests that K hib modifications of these proteins may be the most important regulation pattern in plants.…”

“…In wheat, 6328 K hib sites in 2186 proteins were identified in three replicates from the roots of cultivar Jimai 44 [ 5 ]. However, in the leaves of this wheat cultivar, only 3004 K hib sites in 1104 proteins were identified [ 22 ]. While a similar number of K hib sites and K hib -modified proteins were identified in the leaves of wheat cultivar Ak58, which identified 3348 K hib sites in 1074 proteins [ 21 ].…”

Current perspectives of ubiquitination and SUMOylation in abiotic stress tolerance in plants

“…Histone acetylation regulates gene expression, allowing transcription activation through DNA-binding proteins, and plays a key role under abiotic stresses (Weng et al, 2014 ; Hu et al, 2015 ; Li et al, 2021 ). Recently identified PTM types, such as butyrylation, crotonylation, glutarylation, malonylation, propionylation, succinylation, and 2-hydroxyisobutyrylation, greatly influence the growth, differentiation, and metabolism of plants (Huang et al, 2017 ; Feng et al, 2021 ; Xu et al, 2021 ). Glycosylation has a vital role in protein folding, signaling, intermolecular interactions, cell-cell adhesion, ER signaling, etc.…”