| First Author | Kim DK | Year | 1998 |
| Journal | Blood | Volume | 92 |
| Issue | 6 | Pages | 1973-80 |
| PubMed ID | 9731055 | Mgi Jnum | J:49963 |
| Mgi Id | MGI:1289631 | Doi | 10.1182/blood.v92.6.1973.418k23_1973_1980 |
| Citation | Kim DK, et al. (1998) Impaired expression of integrin alpha-4 subunit in cultured mast cells derived from mutant mice of mi/mi genotype. Blood 92(6):1973-80 |
| abstractText | The mi locus encodes a member of the basic-helix-loop- helix-leucine zipper protein family of transcription factors (hereafter called MITF). We have reported that expression of several genes was impaired in cultured mast cells (CMCs) of mi/mi mice due to a defective transactivation ability of mutant MITF (mi-MITF). Because attachment of mi/mi CMCs to fibroblasts is impaired, we examined the expression of integrin genes in mi/mi CMCs in the present study. Among the integrin genes examined, the expression of integrin alpha 4 subunit was barely detectable in mi/mi CMCs, and the alpha 14 protein was not detected by flow cytometry either. The specific adhesion to vascular cell adhesion molecule-1 (VCAM-1), the ligand for alpha 4 subunit, was observed in +/+ CMCs but not in mi/mi CMCs, indicating that the expression of integrin alpha 4 subunit at a functional level did not occur in mi/mi CMCs. In the promoter region of the alpha 4 subunit gene, there was a CACTTG motif to which normal MITF (+- MITF) bound. The coexpression of +-MITF but not of mi-MITF transactivated the promoter of the alpha 4 subunit gene. The deletion or mutation of the CACTTG motif abolished the transactivation by +-MITF, suggesting that +-MITF directly transactivated the gene encoding alpha 4 subunit of integrin. (C) 1998 by The American Society of Hematology. |
