α-1,6-Fucosyltransferase (FUT8) inhibits hemoglobin production during differentiation of murine and K562 human erythroleukemia cells.

Abstract

Erythropoiesis results from a complex combination of the expression of several transcription factor genes and cytokine signaling. However, the overall view of erythroid differentiation remains unclear. First, we screened for erythroid differentiation-related genes by comparing the expression profiles of high differentiation-inducible and low differentiation-inducible murine erythroleukemia cells. We identified that overexpression of α-1,6-fucosyltransferase (Fut8) inhibits hemoglobin production. FUT8 catalyzes the transfer of a fucose residue to N-linked oligosaccharides on glycoproteins via an α-1,6 linkage, leading to core fucosylation in mammals. Expression of Fut8 was down-regulated during chemically induced differentiation of murine erythroleukemia cells. Additionally, expression of Fut8 was positively regulated by c-Myc and c-Myb, which are known as suppressors of erythroid differentiation. Second, we found that FUT8 is the only fucosyltransferase family member that inhibits hemoglobin production. Functional analysis of FUT8 revealed that the donor substrate-binding domain and a flexible loop play essential roles in inhibition of hemoglobin production. This result clearly demonstrates that core fucosylation inhibits hemoglobin production. Third, FUT8 also inhibited hemoglobin production of human erythroleukemia K562 cells. Finally, a short hairpin RNA study showed that FUT8 down-regulation induced hemoglobin production and increase of transferrin receptor/glycophorin A-positive cells in human erythroleukemia K562 cells. Our findings define FUT8 as a novel factor for hemoglobin production and demonstrate that core fucosylation plays an important role in erythroid differentiation.

• Authors: Hitoshi Sasaki, Takanori Toda, Toru Furukawa, Yuki Mawatari, Rika Takaesu, Masashi Shimizu, Ryohei Wada, Dai Kato, Takahiko Utsugi, Masaya Ohtsu, Yasufumi Murakami
• Journal: The Journal of biological chemistry (J Biol Chem) Vol. 288 Issue 23 Pg. 16839-16847 (Jun 07 2013) ISSN: 1083-351X [Electronic] United States
• PMID: 23609441 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Glycophorins
• Hemoglobins
• MYC protein, human
• Proto-Oncogene Proteins c-myb
• Proto-Oncogene Proteins c-myc
• Fucose
• Fucosyltransferases
• Glycoprotein 6-alpha-L-fucosyltransferase

Topics

• Animals
• Biological Transport, Active (genetics)
• Cell Differentiation
• Fucose (genetics, metabolism)
• Fucosyltransferases (genetics, metabolism)
• Glycophorins (genetics, metabolism)
• Hemoglobins (biosynthesis, genetics)
• Humans
• K562 Cells
• Leukemia, Erythroblastic, Acute (enzymology)
• Mice
• Protein Structure, Tertiary
• Proto-Oncogene Proteins c-myb (genetics, metabolism)
• Proto-Oncogene Proteins c-myc (genetics, metabolism)