Tisp40, a spermatid specific bZip transcription factor, functions by binding to the unfolded protein response element via the Rip pathway.
TISP40, a mouse spermatid-specific gene, encodes a CREB/CREM family transcription factor that is predominantly expressed during spermiogenesis. We report here that TISP40 generates two types of proteins, Tisp40alpha and Tisp40beta, both of which contain a transmembrane domain and localize to the endoplasmic reticulum (ER). In contrast, mutant proteins lacking the transmembrane domain (Tisp40alpha/betaDeltaTM) primarily localize to the nucleus. Endoglycosidase H treatment shows that the C-terminus of Tisp40alpha/beta is glycosylated. Protease experiments demonstrate that Tisp40alpha/beta are Type II transmembrane proteins that are released into the nucleus by a two-step cleavage mechanism called 'regulated intramembrane proteolysis' (Rip). Unlike previously published observations, Tisp40alpha does not bind to the NF-kappaB site; instead, it specifically binds to the unfolded protein response element (UPRE). Luciferase assays reveal that Tisp40betaDeltaTM activates transcription through UPRE. Northern blot analysis shows that Tisp40alpha/betaDeltaTM proteins up-regulate EDEM (ER degradation of enhancing alpha-manosidase-like protein) mRNA. These observations unveil a novel event in mouse spermiogenesis and show that the final stage of transcriptional regulation is controlled by the Rip pathway.
Nagamori
Ippei
I
Department of Molecular Genetics, Research Institute for Microbial Diseases, Osaka University, Yamadaoka 3-1, Suita City, Osaka, Japan.
Yabuta
Norikazu
N
Fujii
Takayuki
T
Tanaka
Hiromitsu
H
Yomogida
Kentaro
K
Nishimune
Yoshitake
Y
Nojima
Hiroshi
H
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000187:drug effects; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006026:Glycoside Hydrolases / Q000494:pharmacology*; D006031:Glycosylation; D006367:HeLa Cells; D006639:Histidine / Q000737:chemistry; D006801:Humans; D007668:Kidney / Q000166:cytology / Q000196:embryology; D016350:Leucine Zippers; D008156:Luciferases / Q000378:metabolism; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D010766:Phosphorylation; D010802:Phylogeny; D011485:Protein Binding / Q000187:drug effects; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D053422:Receptor-Interacting Protein Serine-Threonine Kinases; D020218:Response Elements / Q000235:genetics*; D017384:Sequence Deletion; D013087:Spermatids / Q000378:metabolism*; D013091:Spermatogenesis; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*
D004268:DNA-Binding Proteins; D011506:Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D006639:Histidine; D008156:Luciferases; C506249:RIPK1 protein, human; D053422:Receptor-Interacting Protein Serine-Threonine Kinases; C506251:Ripk1 protein, mouse; D006026:Glycoside Hydrolases