TY  - JOUR
A1  - Sanz-Moreno, Adrian
A1  - Fuhrmann, David
A1  - Wolf, Elmar
A1  - von Eyss, Björn
A1  - Eilers, Martin
A1  - Elsässer, Hans-Peter
T1  - Miz1 Deficiency in the Mammary Gland Causes a Lactation Defect by Attenuated Stat5 Expression and Phosphorylation
JF  - PLOS ONE
N2  - Miz1 is a zinc finger transcription factor with an N-terminal POZ domain. Complexes with Myc, Bcl-6 or Gfi-1 repress expression of genes like Cdkn2b (p15(Ink4)) or Cd-kn1a (p21(Cip1)). The role of Miz1 in normal mammary gland development has not been addressed so far. Conditional knockout of the Miz1 POZ domain in luminal cells during pregnancy caused a lactation defect with a transient reduction of glandular tissue, reduced proliferation and attenuated differentiation. This was recapitulated in vitro using mouse mammary gland derived HC11 cells. Further analysis revealed decreased Stat5 activity in Miz1 Delta POZ mammary glands and an attenuated expression of Stat5 targets. Gene expression of the Prolactin receptor (PrlR) and ErbB4, both critical for Stat5 phosphorylation (pStat5) or pStat5 nuclear translocation, was decreased in Miz1 Delta POZ females. Microarray, ChIP-Seq and gene set enrichment analysis revealed a down-regulation of Miz1 target genes being involved in vesicular transport processes. Our data suggest that deranged intracellular transport and localization of PrlR and ErbB4 disrupt the Stat5 signalling pathway in mutant glands and cause the observed lactation phenotype.
KW  - C-MYC
KW  - transcription factor MIZ-1
KW  - breast-cancer cells
KW  - gene expression
KW  - epithelial cells
KW  - prolactin
KW  - transgenic mice
KW  - growth
KW  - differentiation
KW  - proliferation
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-117286
VL  - 9
IS  - 2
ER  - 
TY  - JOUR
A1  - Rodrigues, Lénia
A1  - Popov, Nikita
A1  - Kaye, Kenneth M.
A1  - Simas, J. Pedro
T1  - Stabilization of Myc through Heterotypic Poly-Ubiquitination by mLANA Is Critical for \(\gamma\)-Herpesvirus Lymphoproliferation
JF  - PLoS PATHOGENS
N2  - Host colonization by lymphotropic \(\gamma\)-herpesviruses depends critically on expansion of viral genomes in germinal center (GC) B-cells. Myc is essential for the formation and maintenance of GCs. Yet, the role of Myc in the pathogenesis of \(\gamma\)-cherpesviruses is still largely unknown. In this study, Myc was shown to be essential for the lymphotropic \(\gamma\)-herpesvirus MuHV- 4 biology as infected cells exhibited increased expression of Myc signature genes and the virus was unable to expand in Myc defficient GC B- cells. We describe a novel strategy of a viral protein activating Myc through increased protein stability resulting in increased progression through the cell cycle. This is acomplished by modulating a physiological posttranslational regulatory pathway of Myc. The molecular mechanism involves Myc heterotypic poly- ubiquitination mediated via the viral E3 ubiquitin- ligase mLANA protein. \(EC_5S^{mLANA}\) modulates cellular control of Myc turnover by antagonizing \(SCF^{Fbw7}\) mediated proteasomal degradation of Myc, mimicking \(SCF^{\beta-TrCP}\). The findings here reported reveal that modulation of Myc is essential for \(\gamma\)-herpesvirus persistent infection, establishing a link between virus induced lymphoproliferation and disease.
KW  - latency
KW  - murine gammaherpesvirus 68
KW  - Epstein-Barr-virus
KW  - C-MYC
KW  - nuclear antigen
KW  - germinal center
KW  - B lymphocytes
KW  - protein
KW  - cells
KW  - beta-TRCP
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-131227
VL  - 9
IS  - 8
ER  -