title: TSA1 interacts with CSN1/CSN and may be functionally involved in Arabidopsis seedling development in darkness.
abstract: The COP9 signalosome (CSN) is a multiprotein complex which participates in diverse cellular and developmental processes. CSN1, one of the subunits of CSN, is essential for assembly of the multiprotein complex via PCI (proteasome, COP9 signalosome and initiation factor 3) domain in the C-terminal half of CSN1. However, the role of the N-terminal domain (NTD) of CSN1, which is critical for the function of CSN, is not completely understood. Using a yeast two-hybrid (Y2H) screen, we found that the NTD of CSN1 interacts with TSK-associating protein 1 (TSA1), a reported Ca(2+)-binding protein. The interaction between CSN1 and TSA1 was confirmed by co-immunoprecipitation in Arabidopsis. tsa1 mutants exhibited a short hypocotyl phenotype in darkness but were similar to wild-type Arabidopsis under white light, which suggested that TSA1 might regulate Arabidopsis hypocotyl development in the dark. Furthermore, the expression of TSA1 was significantly lower in a csn1 null mutant (fus6), while CSN1 expression did not change in a tsa1 mutant with weak TSA1 expression. Together, these findings suggest a functional relationship between TSA1 and CSN1 in seedling development.
authors: State Key Laboratory of Genetic Engineering, Department of Biochemistry, Fudan University, Shanghai, China.
authors: Wenjun
authors: W
authors: Li
authors: Baisheng
authors: B
authors: Zang
authors: Citao
authors: C
authors: Liu
authors: Lu
authors: L
authors: Lu
authors: Ning
authors: N
authors: Wei
authors: Kaiming
authors: K
authors: Cao
authors: Xing Wang
authors: XW
authors: Deng
authors: Xiping
authors: X
authors: Wang
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000075686:COP9 Signalosome Complex; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003624:Darkness; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D036226:Seedlings / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism / Q000528:radiation effects
chemical_list: D029681:Arabidopsis Proteins; C086322:CSN1 protein, Arabidopsis; D002135:Calcium-Binding Proteins; C570658:TSK-associating protein 1, Arabidopsis; D000075686:COP9 Signalosome Complex