PLRG1 is an essential regulator of cell proliferation and apoptosis during vertebrate development and tissue homeostasis.
PLRG1, an evolutionarily conserved component of the spliceosome, forms a complex with Pso4/SNEV/Prp19 and the cell division and cycle 5 homolog (CDC5L) that is involved in both pre-mRNA splicing and DNA repair. Here, we show that the inactivation of PLRG1 in mice results in embryonic lethality at 1.5 days postfertilization. Studies of heart- and neuron-specific PLRG1 knockout mice further reveal an essential role of PLRG1 in adult tissue homeostasis and the suppression of apoptosis. PLRG1-deficient mouse embryonic fibroblasts (MEFs) fail to progress through S phase upon serum stimulation and exhibit increased rates of apoptosis. PLRG1 deficiency causes enhanced p53 phosphorylation and stabilization in the presence of increased gamma-H2AX immunoreactivity as an indicator of an activated DNA damage response. p53 downregulation rescues lethality in both PLRG1-deficient MEFs and zebrafish in vivo, showing that apoptosis resulting from PLRG1 deficiency is p53 dependent. Moreover, the deletion of PLRG1 results in the relocation of its interaction partner CDC5L from the nucleus to the cytoplasm without general alterations in pre-mRNA splicing. Taken together, the results of this study identify PLRG1 as a critical nuclear regulator of p53-dependent cell cycle progression and apoptosis during both embryonic development and adult tissue homeostasis.
Kleinridders
André
A
Institute for Genetics, Department of Mouse Genetics and Metabolism, University of Cologne, Cologne, Germany.
Pogoda
Hans-Martin
HM
Irlenbusch
Sigrid
S
Smyth
Neil
N
Koncz
Csaba
C
Hammerschmidt
Matthias
M
Brüning
Jens C
JC
D000818:Animals; D017209:Apoptosis; D002453:Cell Cycle; D049109:Cell Proliferation; D003433:Crosses, Genetic; D003593:Cytoplasm / Q000378:metabolism; D020964:Embryo Loss / Q000378:metabolism; D004622:Embryo, Mammalian / Q000166:cytology; D047108:Embryonic Development; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D006706:Homeostasis; D008297:Male; D051379:Mice; D032383:Myocytes, Cardiac / Q000166:cytology / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D009687:Nuclear Proteins / Q000172:deficiency / Q000378:metabolism*; D009928:Organ Specificity; D021381:Protein Transport; D016601:RNA-Binding Proteins / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D014714:Vertebrates / Q000196:embryology*; D015027:Zebrafish / Q000196:embryology; D029961:Zebrafish Proteins / Q000172:deficiency / Q000378:metabolism*
D009687:Nuclear Proteins; C541023:Plrg1 protein, mouse; C541024:Plrg1 protein, zebrafish; D016601:RNA-Binding Proteins; D016159:Tumor Suppressor Protein p53; D029961:Zebrafish Proteins