Generation of a conditional knockout allele for mammalian Spen protein Mint/SHARP.
The Spen protein family is found in worms, flies, and mammals, and is implicated in diverse biological processes from embryogenesis to aging. Spen proteins have three N-terminal RNA recognition motifs and a C-terminal SPOC domain. The mammalian Spen proteins Mint and its human ortholog SHARP interact with the Notch-signaling mediator RBP-J as well as Msx2 and several unliganded nuclear hormone receptors, and impart transcription-repressing activity to these molecules by recruiting corepressors through the SPOC domain. Despite these in vitro findings, Mint/SHARP's physiological role is largely unknown, because Mint germline knockouts are embryonic lethal. To analyze Mint/SHARP function in postnatal mice, we created Mint-floxed mice that allow the Cre/loxP-mediated conditional knockout of Mint. We analyzed Mint and RBP-J epistasis during Notch-dependent splenic B-lymphocyte development, and found that Mint suppresses Notch signaling through RBP-J. In addition, Mint deficiency caused severe hypoplasia in postnatal brain, suggesting it may regulate neuronal cell survival.
Yabe
Daisuke
D
Department of Medical Chemistry and Molecular Biology, Kyoto University Graduate School of Medicine, Kyoto, Japan.
Fukuda
Hitoshi
H
Aoki
Misayo
M
Yamada
Shuichi
S
Takebayashi
Shinji
S
Shinkura
Reiko
R
Yamamoto
Norio
N
Honjo
Tasuku
T
D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000378:metabolism; D001921:Brain / Q000378:metabolism / Q000473:pathology; D004268:DNA-Binding Proteins / Q000378:metabolism; D018390:Gene Targeting / Q000379:methods; D018398:Homeodomain Proteins / Q000235:genetics; D006801:Humans; D017403:In Situ Hybridization; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D018345:Mice, Knockout; D008822:Mice, Transgenic; D009687:Nuclear Proteins / Q000172:deficiency* / Q000235:genetics* / Q000378:metabolism; D016601:RNA-Binding Proteins; D051880:Receptors, Notch / Q000378:metabolism; D015398:Signal Transduction
D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; C484553:Rbpsuhl protein, mouse; D051880:Receptors, Notch; C476510:SPEN protein, human; C121253:Spen protein, mouse