NUP1 modulates proteasome based degradation of ABI5 in Nuclear Pore Complex region to regulate Arabidopsis seed germination
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ABSTRACT: NUCLEOPORIN 1 (NUP1), a member of the Nuclear Pore Complex (NPC), is located on the inner side of the nuclear membrane. It is highly expressed in seeds; however, its role in seeds including germination has not been explored yet. Here, we identified an ABA hypersensitive phenotype of nup1 during germination. ABA treatment drastically changes the expression pattern of thousands of genes in nup1, including the major transcription factors (TFs) involved in germination, ABI3, ABI4, and ABI5. Double mutant analysis of NUP1 and these ABA-related genes showed that mutations in ABI5 can rescue the phenotype of nup1, suggesting that NUP1 acts upstream of ABI5 to regulate seed germination. ABI5, a negative regulator of germination was previously reported to be predominantly expressed in nucleus. Our subnuclear localization study indicates ABI5 is mostly localized in nucleoplasm. It is abundant in dry seeds and rapidly degraded during germination, but the details of its degradation site is unclear. Here, we found that NUP1 is physically associated with ABI5 and the 19S regulatory particle (RP) of the 26S proteasome near NPC. Mutation in NUP1 delayed the ABI5 degradation through its post-translation retention in nucleolus after abiotic stress treatment. Taken together, we propose, NUP1 anchors the proteasome to NPC and modulates Arabidopsis seed germination through proteasome-mediated degradation of ABI5 in the vicinity of NPC in nucleoplasm.
ORGANISM(S): Arabidopsis thaliana
PROVIDER: GSE189513 | GEO | 2023/08/14
REPOSITORIES: GEO
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