HEK293 cells express dystrophin Dp71 with nucleus-specific localization of Dp71ab.
The dystrophin gene consists of 79 exons and encodes tissue-specific isoforms. Mutations in the dystrophin gene cause Duchenne muscular dystrophy, of which a substantial proportion of cases are complicated by non-progressive mental retardation. Abnormalities of Dp71, an isoform transcribed from a promoter in intron 62, are a suspected cause of mental retardation. However, the roles of Dp71 in human brain have not been fully elucidated. Here, we characterized dystrophin in human HEK293 cells with the neuronal lineage. Reverse transcription-PCR amplification of the full-length dystrophin transcript revealed the absence of fragments covering the 5' part of the dystrophin cDNA. In contrast, fragments covering exons 64-79 were present. The Dp71 promoter-specific exon G1 was shown spliced to exon 63. We demonstrated that the Dp71 transcript comprised two subisoforms: one lacking exon 78 (Dp71b) and the other lacking both exons 71 and 78 (Dp71ab). Western blotting of cell lysates using an antibody against the dystrophin C-terminal region revealed two bands, corresponding to Dp71b and Dp71ab. Immunohistochemical examination with the dystrophin antibody revealed scattered punctate signals in the cytoplasm and the nucleus. Western blotting revealed one band corresponding to Dp71b in the cytoplasm and two bands corresponding to Dp71b and Dp71ab in the nucleus, with Dp71b being predominant. These results indicated that Dp71ab is a nucleus-specific subisoform. We concluded that Dp71, comprising Dp71b and Dp71ab, was expressed exclusively in HEK293 cells and that Dp71ab was specifically localized to the nucleus. Our findings suggest that Dp71ab in the nucleus contributes to the diverse functions of HEK293 cells.
Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani, Nishi, Kobe, 651-2180, Japan.
Atsushi
A
Nishida
Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani, Nishi, Kobe, 651-2180, Japan.|Kobe Pharmaceutical University, Higashinada, Kobe, 658-8558, Japan.
Sato
S
Yasuno
Kobe Pharmaceutical University, Higashinada, Kobe, 658-8558, Japan.
Atsuko
A
Takeuchi
Department of Pediatrics, Graduate School of Medicine, Kobe University, Chuo, Kobe, 650-0017, Japan.
Hiroyuki
H
Awano
Department of Pediatrics, Hyogo College of Medicine, Mukogawacho, Nishinomiya, 663-8501, Japan.
Tomoko
T
Lee
Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani, Nishi, Kobe, 651-2180, Japan.
Emma Tabe Eko
ET
Niba
Department of Pathology and Applied Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan.
Takahiro
T
Fujimoto
Department of Pathology and Applied Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, 602-8566, Japan.
Kyoko
K
Itoh
Department of Pediatrics, Hyogo College of Medicine, Mukogawacho, Nishinomiya, 663-8501, Japan.
Yasuhiro
Y
Takeshima
Department of Community Medicine and Social Healthcare Science, Graduate School of Medicine, Kobe University, Chuo, Kobe, 650-0017, Japan.
Hisahide
H
Nishio
Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani, Nishi, Kobe, 651-2180, Japan. mmatsuo@reha.kobegakuin.ac.jp.
Masafumi
M
Matsuo
D002467:Cell Nucleus / Q000378:metabolism*; D016189:Dystrophin / Q000032:analysis / Q000235:genetics* / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D020033:Protein Isoforms / Q000032:analysis / Q000235:genetics / Q000378:metabolism
D016189:Dystrophin; D020033:Protein Isoforms; C085339:apo-dystrophin 1
Dp71; Dp71ab; Dystrophin; HEK293 cells; Nucleus