Human DDX3Y, the Y-encoded isoform of RNA helicase DDX3, rescues a hamster temperature-sensitive ET24 mutant cell line with a DDX3X mutation.
We investigated the function of DDX3Y, the Y chromosome AZFa region encoding a putative DEAD-box RNA helicase protein, the loss of which results in oligozoospermia or azoospermia in humans. The human DDX3Y amino acid sequence is similar to that of the X chromosome gene DDX3X (91.7% homology). Here we report that human Y- and X-encoded DEAD box RNA helicase proteins DDX3Y and DDX3X are interchangeable and have an essential function: both proteins rescued a temperature-sensitive mutant hamster cell line (tsET24) that was otherwise incapable of growth at a nonpermissive temperature. Mouse homologues Ddx3y and D1Pas1-PL10 also rescued the mutant cell line at a nonpermissive temperature. In situ hybridization revealed that Ddx3x mRNA was expressed in almost every cell in mouse testis, suggesting that Ddx3x is involved in spermatogenesis. A comparative study of DDX3X and DDX3Y was performed to determine the significance of DDX3Y for cell growth and spermatogenesis. Both DDX3X and DDX3Y promoter DNAs produced a similar degree of transcription in vivo, whereas deletion studies of the promoter DNAs indicated that these genes are differentially regulated. DDX3Y, similar to DDX3X, shuttles between the nucleus and cytoplasm in a crm1-dependent manner.
Sekiguchi
Takeshi
T
Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582, Japan. sekigu@molbiol.med.kyushu-u.ac.jp
Iida
Hiroshi
H
Fukumura
Junko
J
Nishimoto
Takeharu
T
D021581:Active Transport, Cell Nucleus / Q000235:genetics; D000818:Animals; D002460:Cell Line; D041322:Chromosomes, Human, Y / Q000235:genetics*; D006224:Cricetinae; D053487:DEAD-box RNA Helicases; D005260:Female; D005809:Genes, Regulator / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D028884:Karyopherins / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D015778:Minor Histocompatibility Antigens; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D011506:Proteins / Q000235:genetics* / Q000378:metabolism*; D012313:RNA / Q000235:genetics / Q000378:metabolism*; D020365:RNA Helicases / Q000235:genetics / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D013090:Spermatocytes / Q000201:enzymology; D013091:Spermatogenesis / Q000235:genetics; D013696:Temperature; D014158:Transcription, Genetic / Q000235:genetics; D000097606:Exportin 1 Protein
D053487:DEAD-box RNA Helicases; D028884:Karyopherins; D015778:Minor Histocompatibility Antigens; D020033:Protein Isoforms; D011506:Proteins; D012313:RNA; D020365:RNA Helicases; D018160:Receptors, Cytoplasmic and Nuclear; D000097606:Exportin 1 Protein; C059787:D1Pas1 protein, mouse; C119332:DDX3X protein, human; C492034:DDX3Y protein, human; C115600:Ddx3y protein, mouse