Yu Haiyang, Zhang Yu, Zhang Dong, Lu Yanxi, He Haixia, Zheng Fucong, Wang Meng
Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, Institute of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China.
Int J Mol Sci. 2017 Mar 30;18(4):617. doi: 10.3390/ijms18040617.
5-Phospho-d-ribosyl-1-diphosphate (PRPP) synthase (PRS) catalyzes the biosynthesis of PRPP, which is an important compound of metabolism in most organisms. However, no genes have been cloned, let alone studied for their biological function in rubber tree. In this study, we identify a novel protein (PRS4) that interacts in vivo with rubber tree anaphase promoting complex/cyclosome (APC/C) subunit 10 (HbAPC10) by yeast two-hybrid assays. has been cloned from rubber tree and named as . Blastp search in the genome of showed that HbPRS4 shared the highest similarity with AtPRS4, with 80.71% identity. qRT-PCR was used to determine the expression of in different tissues and under various treatments. was preferentially expressed in the bark. Moreover, the expression level of was significantly induced by the proteasome inhibitor MG132 treatment, suggesting it might be regulated by the ubiquitin/26S proteasome pathway. The amount of transcript was obviously decreased after mechanical wounding and abscisic acid (ABA) treatments, while a slight increase was observed at 24 h after ABA treatment. transcript in the latex was significantly upregulated by ethephon (ET) and methyl jasmonate (MeJA) treatments. These results suggested that HbPRS4 may be a specific substrate of HbAPC10 indirectly regulating natural rubber biosynthesis in rubber tree.
5-磷酸-D-核糖-1-二磷酸（PRPP）合酶（PRS）催化PRPP的生物合成，PRPP是大多数生物体新陈代谢中的一种重要化合物。然而，尚未克隆到橡胶树中的相关基因，更不用说对其生物学功能进行研究了。在本研究中，我们通过酵母双杂交试验鉴定出一种与橡胶树后期促进复合体/细胞周期体（APC/C）亚基10（HbAPC10）在体内相互作用的新型蛋白质（PRS4）。已从橡胶树中克隆出该基因并命名为 。在 的基因组中进行Blastp搜索表明，HbPRS4与AtPRS4的相似性最高，同一性为80.71%。采用qRT-PCR法测定该基因在不同组织和各种处理条件下的表达情况。该基因在树皮中优先表达。此外，蛋白酶体抑制剂MG132处理显著诱导了该基因的表达水平，表明它可能受泛素/26S蛋白酶体途径调控。机械损伤和脱落酸（ABA）处理后，该基因的转录本量明显减少，而在ABA处理24小时后观察到略有增加。乙烯利（ET）和茉莉酸甲酯（MeJA）处理显著上调了胶乳中该基因的转录本。这些结果表明，HbPRS4可能是HbAPC10的特异性底物，并间接调控橡胶树中天然橡胶的生物合成。
