In-depth proteome analysis of the rubber particle of Hevea brasiliensis (para rubber tree)

Abstract

The rubber particle is a special organelle in which natural rubber is synthesised and stored in the laticifers of Hevea brasiliensis. To better understand the biological functions of rubber particles and to identify the candidate rubber biosynthesis-related proteins, a comprehensive proteome analysis was performed on H. brasiliensis rubber particles using shotgun tandem mass spectrometry profiling approaches-resulting in a thorough report on the rubber particle proteins. A total of 186 rubber particle proteins were identified, with a range in relative molecular mass of 3.9-194.2 kDa and in isoelectric point values of 4.0-11.2. The rubber particle proteins were analysed for gene ontology and could be categorised into eight major groups according to their functions: including rubber biosynthesis, stress- or defence-related responses, protein processing and folding, signal transduction and cellular transport. In addition to well-known rubber biosynthesis-related proteins such as rubber elongation factor (REF), small rubber particle protein (SRPP) and cis-prenyl transferase (CPT), many proteins were firstly identified to be on the rubber particles, including cyclophilin, phospholipase D, cytochrome P450, small GTP-binding protein, clathrin, eukaryotic translation initiation factor, annexin, ABC transporter, translationally controlled tumour protein, ubiquitin-conjugating enzymes, and several homologues of REF, SRPP and CPT. A procedure of multiple reaction monitoring was established for further protein validation. This comprehensive proteome data of rubber particles would facilitate investigation into molecular mechanisms of biogenesis, self-homeostasis and rubber biosynthesis of the rubber particle, and might serve as valuable biomarkers in molecular breeding studies of H. brasiliensis and other alternative rubber-producing species.

Hevea brasiliensis REF (Hev b 1) and SRPP (Hev b 3): An overview on rubber particle proteins

“…A recent study identified 186 rubber particle proteins [25], but latex contains far more proteins, from which at least 15 have been internationally assigned as allergens named Hev b 1-15 (Table 2; [111,112]). REF and SRPP are recognized as major allergens found in latex [29,37,71,102,110].…”

“…A proteome analysis revealed the presence of more than 1300 protein spots in latex and nearly 600 in rubber particles [24]. In 2013, Dai et al identified 186 different proteins in rubber particles [25]. As seen on a polyacrylamide gel electrophoresis stained by Coomassie Blue (Fig.…”

Quantitative Analysis of AntiHevea brasiliensis Antibody Cross-Reactivity against Taraxacum kok-saghyz Latex Proteins Demonstrates Significantly Reduced Antibody Recognition

“…The rubber particle of H. brasiliensis contains at least 186 proteins based on proteomic analysis [27], while the whole cytoplasm latex of H. brasiliensis contains over 300 proteins [24], including 15 that have been identified thus far as being clinically significant in human type I latex allergy. These 15 proteins represent the canonical Hevea allergens, named Hev b 1 through Hev b 15 by the World Health Organization International Union of Immunological Studies (IUIS) (http://www.…”

Highlights on Hevea brasiliensis (pro)hevein proteins

“…The draft genome sequence of H. brasiliensis was achieved in 2013, identifying 16 Hev b 6 genes [14]. The presence of hevein isoforms has been shown by several studies at all levels of expression (genes, mRNA and proteins).…”

“…To date, 1,499 proteins have been found in latex [12,13]. At least 186 proteins have been reported to be present on rubber particles [14] and 169 have been extracted from lutoids and the bottom fractions [15]. Hevein belongs to the lutoid proteins and represents approximately 20% of the dry matter of the bottom fractions [16,17].…”