Characterization of a novel transcript of 14-3-3 theta in Sertoli cells.
The isoforms of the highly conserved and ubiquitously expressed 14-3-3 family of proteins function primarily as adapters that modulate interactions between components of various cellular signaling and cell cycle regulatory pathways. Low levels of 14-3-3 isoforms appear to be expressed in most tissues, but specific isoforms or combinations have been shown to be overexpressed in a cell-specific manner. In the present study we show that the theta isoform of 14-3-3 is expressed in Sertoli cells. Although previous reports have shown the presence of a 14-3-3 theta isoform in mouse testicular germ cells, this report demonstrates the presence of the 14-3-3 theta isoform in rat Sertoli cells. The 14-3-3 theta isoform isolated from rat Sertoli cells appears to have a truncated 3' UTR, which makes the transcript shorter by 244 bp, compared with its brain counterpart. Northern blot analysis suggests that the 14-3-3 theta isoform may also be present in other testicular cell types and tissues. The truncation of the 3' UTR suggests a potential role in regulating cell-specific expression of 14-3-3 theta. The expression of 14-3-3 theta in Sertoli cells was confirmed by Northern blot, polymerase chain reaction, Western blot, and immunocytochemical analysis. The levels of 14-3-3 theta mRNA and protein in Sertoli cells remained unchanged in response to the gonadotropin, FSH. Consistent with the absence of the effect of FSH on the expression of 14-3-3 theta, an antisense oligonucleotide to 14-3-3 theta had no effect on FSH-induced activation of the transferrin promoter in Sertoli cells. The widespread expression of 14-3-3 theta in testis and the lack of effect of FSH on levels of its expression suggest that 14-3-3 theta influences Sertoli cell function in an FSH-independent manner.
Chaudhary
J
J
Center for Reproductive Biology, School of Molecular Biosciences, Washington State University, Pullman 99164-4231, USA.
Skinner
M K
MK
D048948:14-3-3 Proteins; D020413:3' Untranslated Regions / Q000235:genetics; D000818:Animals; D001483:Base Sequence / Q000235:genetics; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D008297:Male; D008969:Molecular Sequence Data; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D011401:Promoter Regions, Genetic / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics* / Q000302:isolation & purification; D051381:Rats; D012708:Sertoli Cells / Q000187:drug effects / Q000378:metabolism*; D014168:Transferrin / Q000235:genetics; D014446:Tyrosine 3-Monooxygenase / Q000235:genetics*
D048948:14-3-3 Proteins; D020413:3' Untranslated Regions; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D014168:Transferrin; D005640:Follicle Stimulating Hormone; D014446:Tyrosine 3-Monooxygenase