Involvement of NUCLEOPORIN1 in cell division and expansion in Arabidopsis

NUCLEOPORIN1 (NUP1), a component of the nuclear pore complex and an anchor for the TREX-2 mRNA export complex, was previously reported to have diverse functions in Arabidopsis. Several studies have shown that mutations in NUP1 lead to small stature plants with small leaves; however, the underlying mechanism is unknown. Here, we investigated the small leaf phenotype of nup1-1 plants and found that cell number and size are reduced. Next, gene expression analysis revealed significant changes in the expression of several cell-cycle and expansion-related genes in leaves of nup1-1 plants compared to the wild-type control (Col-0). Furthermore, the subcellular localization of NUP1 throughout mitosis uncovered the potential role of NUP1 in aligning the chromosome during metaphase and separation of chromosomes in anaphase. Our findings suggest that NUP1 is required for maintaining normal plant stature by regulating cell size and number. Further protein-protein interaction of NUP1 and metaphase-anaphase-related proteins would help identify the precise roles of NUP1 in cell division.