GRIP1tau, a novel PDZ domain-containing transcriptional activator, cooperates with the testis-specific transcription elongation factor SII-T1.
SII-T1 is a tissue-specific member of the transcription elongation factor S-II that is expressed specifically in male germ cells. In the present study, we have identified a protein named GRIP1tau interacting with SII-T1 by yeast two-hybrid screening. GRIP1tau is a novel isoform of glutamate receptor-interacting protein 1 (GRIP1) that associates with the cytoplasmic domain of the alpha-amino-3-hydroxy-5-methyl-4-isoaxazolepropionate (AMPA)-type glutamate receptor. GRIP1tau is a testis-specific nuclear protein that activates transcription when fused with a GAL4 DNA binding domain in GAL4-responsive reporter gene assays. The transactivation domain of GRIP1tau overlapped with the region essential for interaction with SII-T1, as revealed by co-immunoprecipitation assays. Also, transactivation by GRIP1tau was stimulated by SII-T1 in a dose-dependent manner. Therefore, we propose that GRIP1tau is a novel testis-specific transcriptional activator regulated by interaction with the testis-specific transcription elongation factor SII-T1.
Nakata
Akihito
A
Department of Developmental Biochemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Ito
Takahiro
T
Nagata
Makiko
M
Hori
Sayaka
S
Sekimizu
Kazuhisa
K
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000378:metabolism*; D017931:DNA Primers; D005455:Fluorescent Antibody Technique; D047468:Immunoprecipitation; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D011485:Protein Binding; D020033:Protein Isoforms / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D013737:Testis / Q000378:metabolism*; D015533:Transcriptional Activation; D035602:Transcriptional Elongation Factors / Q000737:chemistry / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D017931:DNA Primers; C491309:Grip1 protein, mouse; D009419:Nerve Tissue Proteins; D020033:Protein Isoforms; D035602:Transcriptional Elongation Factors; C018648:transcription factor S-II