title: Plzf regulates germline progenitor self-renewal by opposing mTORC1.
abstract: Hyperactivity of mTORC1, a key mediator of cell growth, leads to stem cell depletion, although the underlying mechanisms are poorly defined. Using spermatogonial progenitor cells (SPCs) as a model system, we show that mTORC1 impairs stem cell maintenance by a negative feedback from mTORC1 to receptors required to transduce niche-derived signals. We find that SPCs lacking Plzf, a transcription factor essential for SPC maintenance, have enhanced mTORC1 activity. Aberrant mTORC1 activation in Plzf(-/-) SPCs inhibits their response to GDNF, a growth factor critical for SPC self-renewal, via negative feedback at the level of the GDNF receptor. Plzf opposes mTORC1 activity by inducing expression of the mTORC1 inhibitor Redd1. Thus, we identify the mTORC1-Plzf functional interaction as a critical rheostat for maintenance of the spermatogonial pool and propose a model whereby negative feedback from mTORC1 to the GDNF receptor balances SPC growth with self-renewal.
authors.affiliation: Cancer Genetics Program, Beth Israel Deaconess Cancer Center, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Robin M
authors.initials: RM
authors.lastname: Hobbs
authors.forename: Marco
authors.initials: M
authors.lastname: Seandel
authors.forename: Ilaria
authors.initials: I
authors.lastname: Falciatori
authors.forename: Shahin
authors.initials: S
authors.lastname: Rafii
authors.forename: Pier Paolo
authors.initials: PP
authors.lastname: Pandolfi
mesh_terms: D000818:Animals; D025461:Feedback, Physiological; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000378:metabolism; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors / Q000378:metabolism; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000378:metabolism*; D008297:Male; D000076222:Mechanistic Target of Rapamycin Complex 1; D051379:Mice; D046912:Multiprotein Complexes; D000075722:Promyelocytic Leukemia Zinc Finger Protein; D011506:Proteins; D015398:Signal Transduction; D013093:Spermatogonia / Q000166:cytology* / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism; D058570:TOR Serine-Threonine Kinases; D013737:Testis / Q000166:cytology; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D051741:Kruppel-Like Transcription Factors; D046912:Multiprotein Complexes; D000075722:Promyelocytic Leukemia Zinc Finger Protein; D011506:Proteins; D014157:Transcription Factors; C513267:Zbtb16 protein, mouse; D000076222:Mechanistic Target of Rapamycin Complex 1; D058570:TOR Serine-Threonine Kinases