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ISSN 1672-9145                                                Acta Biochim Biophys Sin 2005, 37(4): 241–247                                                   CN 31-1940/Q


Identification of the Alternative Promoters of the KChIP4 Subfamily

Xiao-Yun DENG, Fang CAI, Kun XIA*, Qian PAN, Zhi-Gao LONG, Ling-Qian WU, De-Sheng LIANG, He-Ping DAI, Zhuo-Hua ZHANG, and Jia-Hui XIA

 

National Laboratory of Medical Genetics, Central South University, Changsha 410078, China

 

Abstract        The subfamily of voltage-dependent potassium (Kv) channel interacting protein 4 (KChIP4) is made up of the auxiliary interacting protein of voltage-dependent potassium channels. In this study, the structure of four splicing variants of the human KChIP4 gene was analyzed. Three of the four isoforms of the KChIP4 gene, KChIP4.1, KChIP4.2 and KChIP4.4, were amplified from mouse and human fetal brain tissues by reverse transcription-polymerase chain reaction and then identified. Based on the bioinformatics analysis of the genomic sequences of the gene, we cloned and characterized two promoter fragments from the KChIP4 gene. One was a 325 bp fragment upstream of the 5' end of the KChIP4.1 mRNA sequence and the other was an 818 bp fragment located immediately at the 5' end of the KChIP4.4 variant. Both of them can initiate the transcription of the reporter gene in HT1080 cells and Sprague-Dawley (SD) rat fetal brain neurons, and they contain C+G islands, except typical TATA boxes and CAAT boxes. This shows that the KChIP4 gene expression is regulated by an alternative promoter.

 

Key words        splicing variant; alternative promoter; transcriptional regulation

 

 

 

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Received: December 14, 2004        Accepted: February 25, 2005

This work was supported by the National High Technology Research and Development Program of China (2002BA711A07-08), the Major State Basic Research Development Program of China (2004CB518601), and National Natural Science Foundation of China (30300101, 30123006, and 30400226)

*Corresponding author: Tel, 86-731-4472093; Fax, 86-731-4478152; E-mail, [email protected]