A novel hsp110-related gene, apg-1, that is abundantly expressed in the testis responds to a low temperature heat shock rather than the traditional elevated temperatures.
We isolated a novel hsp110-related gene, apg-1, from a testis cDNA library. The apg-1 transcripts were constitutively expressed in the testicular germ cells and, in some degree, most tissues examined. In a mouse TAMA26 Sertoli cell line, apg-1 transcripts were induced in 2 h by a temperature shift from 32 to 39 degrees C, but not by a shift from 37 to 42 degrees C, the traditional heat stress, or a shift from 32 to 42 degrees C. The heat response pattern of hsp110 expression was similar to that of apg-1. Although induction of a hsp70 transcript was observed in 2 h by a shift from 32 to 39 degrees C, the induction was more apparent by a shift from 37 to 42 degrees C or from 32 to 42 degrees C. Essentially similar differential response patterns were observed among these genes in NIH/3T3 fibroblasts as well. The nuclear run-on assay and the native gel mobility shift assay demonstrated that, by the 32 to 39 degrees C temperature shift, the apg-1 gene was transcriptionally activated, and heat shock factor 1 bound to the heat shock elements in the 5'-flanking region of the apg-1 gene. These results demonstrated that expressions of apg-1, hsp110, and hsp70 could be heat-induced at a temperature lower than the traditional elevated temperatures in somatic cells of both testis and nontestis origin and suggest that the mechanisms regulating the transcript levels of apg-1 and hsp110 are different from those of hsp70. Furthermore, the constitutive expression in germ cells suggests that APG-1 plays a specific role in spermatogenesis as well as in stress response.
Kaneko
Y
Y
Department of Clinical Molecular Biology, Faculty of Medicine, Kyoto University, Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606, Japan.
Nishiyama
H
H
Nonoguchi
K
K
Higashitsuji
H
H
Kishishita
M
M
Fujita
J
J
D016475:3T3 Cells; D000375:Aging / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001853:Bone Marrow; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D003001:Cloning, Molecular; D003080:Cold Temperature; D018076:DNA, Complementary; D015723:Gene Library; D050957:HSP110 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis / Q000737:chemistry*; D006360:Heat-Shock Proteins / Q000096:biosynthesis* / Q000737:chemistry; D006358:Hot Temperature; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D012708:Sertoli Cells; D013737:Testis / Q000254:growth & development / Q000378:metabolism*; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D018076:DNA, Complementary; D050957:HSP110 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D011994:Recombinant Proteins; C099678:Hspa4l protein, mouse