Expression and distribution of symplekin regulates the assembly and function of the epithelial tight junction

Key Laboratory of Animal Models and Human Disease Mechanism of CAS and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, 32 Jiaochang Donglu, Kunming, Yunnan 650223, Peoples' Republic of China.
Histochemie (Impact Factor: 3.05). 01/2012; 137(3):319-27. DOI: 10.1007/s00418-011-0906-z
Source: PubMed


Symplekin is multifunctional protein localized to both the tight junction and the nucleus with known roles in mRNA polyadenylation, proliferation, differentiation and tumorigenesis. Functions of symplekin at tight junctions have not been systematically investigated. In this study, increased expression of symplekin was observed during the formation of tight junctions in cultured HT-29 and HepG2 epithelial cells. Repression of symplekin by RNAi increased the permeability of epithelial monolayers, disrupted cellular polarity, and decreased the expression of the tight junction protein ZO-1. Moreover, symplekin was co-localized with ZO-1 at tight junctions and co-immunoprecipitated with ZO-1, indicating that ZO-1 and symplekin form complexes. In conclusion, symplekin expression regulates the assembly of tight junctions, thus helps to maintain the integrity of the epithelial monolayer and cellular polarity.

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    • "Further exploration should be oriented to establish which proteins could be involved. Possible candidates for such task could be ZO-2, which in concert with ZO-1, adducins and symplekin, regulate TJ organization (Chang et al., 2012; Fanning et al., 2012; Naydenov and Ivanov, 2010). "
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