[Cloning of tight junction protein claudin-1 and construction of the mammalian expression vector].

OBJECTIVE: To construct a recombinant plasmid containing the coding region of tight junction protein claudin-1 gene to understand the functional role of claudin-1 in human colorectal carcinoma. METHODS: The total RNA was extracted using Trizol from human colorectal carcinoma cell line SW620, and the DNA for claudin-1 was obtained by means of RT-PCR. The PCR product was inserted into the plasmid pEGFP-C1 after restriction endonuclease digestion and ligation. The recombinant plasmid was then transfected into human colorectal carcinoma cell line SW480. RESULTS: The sequence of the recombinant plasmid was verified by restriction endonuclease and DNA sequence analysis, and the target protein expression was detected mostly on the cell membrane. CONCLUSION: The expression vector claudin-1/pEGFP-C1 has been constructed successfully and the target protein can be expressed in human colorectal carcinoma cell line.