Effect of a large deletion of the basic domain of mi transcription factor on differentiation of mast cells.
The mi transcription factor (MITF) is a basic-helix-loop-helix-leucine zipper transcription factor that is important for the development of mast cells. Cultured mast cells (CMCs) of mi/mi genotype express abnormal MITF (mi-MITF), but CMCs of tg/tg genotype do not express any MITFs. It was previously reported that mi/mi CMCs showed more severe abnormalities than tg/tg CMCs, indicating that mi-MITF had inhibitory function. Whereas mi-MITF contains a single amino acid deletion in the basic domain, MITF encoded by mi(ew) allele (ew-MITF) deletes 16 of 21 amino acids of the basic domain. Here the effect of a large deletion of the basic domain was examined. In mi(ew)/mi(ew) CMCs, the expression pattern of genes whose transcription was affected by MITF was comparable to that of tg/tg CMCs rather than to that of mi/mi CMCs. This suggested that ew-MITF lacked any functions. The part of the basic domain deleted in ew-MITF appeared necessary for either transactivation or inhibition of transactivation.
Morii
E
E
Department of Pathology, Osaka University Medical School, Suita, Japan. morii@patho.med.osaka-u.ac.jp
Ogihara
H
H
Oboki
K
K
Kataoka
T R
TR
Maeyama
K
K
Fisher
D E
DE
Lamoreux
M L
ML
Kitamura
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D002454:Cell Differentiation / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D018257:Helix-Loop-Helix Motifs; D008156:Luciferases / Q000235:genetics; D008407:Mast Cells / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D051739:Microphthalmia-Associated Transcription Factor; D008969:Molecular Sequence Data; D010957:Plasmids; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012701:Serotonin / Q000378:metabolism; D012867:Skin / Q000166:cytology; D012868:Skin Abnormalities / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014162:Transfection
D004268:DNA-Binding Proteins; D051739:Microphthalmia-Associated Transcription Factor; C497235:Mitf protein, mouse; D014157:Transcription Factors; D012701:Serotonin; D008156:Luciferases