TY - JOUR
T1 - Alternative promoters regulate transcription of the gene that encodes stem cell surface protein AC133
AU - Shmelkov, Sergey V.
AU - Jun, Lin
AU - St. Clair, Ryan
AU - McGarrigle, Deirdre
AU - Derderian, Christopher A.
AU - Usenko, Jaroslav K.
AU - Costa, Carla
AU - Zhang, Fan
AU - Guo, Xinzheng
AU - Rafil, Shahin
PY - 2004/3/15
Y1 - 2004/3/15
N2 - AC133 is a member of a novel family of cell surface proteins with 5 transmembrane domains. The function of AC133 is unknown. Although AC133 mRNA is detected in different tissues, its expression in the hematopoietic system is restricted to CD34+ stem cells. AC133 is also expressed on stem cells of other tissues, including endothelial progenitor cells. However, despite the potential importance of AC133 to the field of stem cell biology, nothing is known about the transcriptional regulation of AC133 expression. In this report we showed that the human AC133 gene has at least 9 distinctive 5′-untranslated region (UTR) exons, resulting in the formation of at least 7 alternatively spliced 5′-UTR isoforms of AC133 mRNA, which are expressed in a tissue-dependent manner. We found that transcription of these AC133 isoforms is controlled by 5 alternative promoters, and we demonstrated their activity on AC133-expressing cell lines using a luciferase reporter system. We also showed that in vitro methylation of 2 of these AC133 promoters completely suppresses their activity, suggesting that methylation plays a role in their regulation. Identification of tissue-specific AC133 promoters may provide a novel method to isolate tissue-specific stem and progenitor cells.
AB - AC133 is a member of a novel family of cell surface proteins with 5 transmembrane domains. The function of AC133 is unknown. Although AC133 mRNA is detected in different tissues, its expression in the hematopoietic system is restricted to CD34+ stem cells. AC133 is also expressed on stem cells of other tissues, including endothelial progenitor cells. However, despite the potential importance of AC133 to the field of stem cell biology, nothing is known about the transcriptional regulation of AC133 expression. In this report we showed that the human AC133 gene has at least 9 distinctive 5′-untranslated region (UTR) exons, resulting in the formation of at least 7 alternatively spliced 5′-UTR isoforms of AC133 mRNA, which are expressed in a tissue-dependent manner. We found that transcription of these AC133 isoforms is controlled by 5 alternative promoters, and we demonstrated their activity on AC133-expressing cell lines using a luciferase reporter system. We also showed that in vitro methylation of 2 of these AC133 promoters completely suppresses their activity, suggesting that methylation plays a role in their regulation. Identification of tissue-specific AC133 promoters may provide a novel method to isolate tissue-specific stem and progenitor cells.
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U2 - 10.1182/blood-2003-06-1881
DO - 10.1182/blood-2003-06-1881
M3 - Article
C2 - 14630820
AN - SCOPUS:12144291514
SN - 0006-4971
VL - 103
SP - 2055
EP - 2061
JO - Blood
JF - Blood
IS - 6
ER -