The Tomato bushy stunt virus-encoded P19 forms dimers that bind duplex short interfering RNAs (siRNAs) to suppress RNA silencing. P19 is also involved in multiple host-specific activities, including the elicitation of symptoms, and in local and/or systemic spread. To study the correlation between those various roles and the siRNA binding by P19, predicted siRNA-interacting sites were modified. ...

Large quantities of an unusual 19 kDa protein (p19) are secreted into the lumen of the uterus of the mare (Equus caballus) during the oestrous cycle and early pregnancy. p19 associates strongly with the acellular capsule that surrounds the young horse conceptus and is believed to be important in maintaining pregnancy. Here we report the complete cDNA sequence encoding p19, its expression patter...

The P19 protein of tomato bushy stunt virus (TBSV) is a multifunctional pathogenicity determinant involved in suppression of posttranscriptional gene silencing, virus movement, and symptom induction. Here, we report that P19 interacts with the conserved RNA-binding domain of an as yet uncharacterized family of plant ALY proteins that, in animals, are involved in export of RNAs from the nucleus ...

The modes of proliferation and differentiation of neural stem cells (NSCs) are coordinately controlled during development, but the underlying mechanisms remain largely unknown. In this study, we show that the protooncoprotein Myc and the tumor suppressor p19(ARF) regulate both NSC self-renewal and their neuronal and glial fate in a developmental stage-dependent manner. Early-stage NSCs have low...

Hematopoietic stem cells (HSCs) are characterized by the capacity for self-renewal and the ability to reconstitute the entire hematopoietic compartment. Thrombopoietin maintains adult HSCs in a quiescent state through the induction of cell cycle inhibitors p57(Kip2) and p19(INK4d). Using the p19(INK4d-/-) mouse model, we investigated the role of p19(INK4d) in basal and stress-induced hematopoie...

Transcription factor Foxm1 plays a critical role during embryonic development and its expression is repressed during retinoic acid (RA)-induced differentiation of pluripotent P19 embryonal carcinoma cells at the early stage, correlated with downregulation of expression of pluripotency markers. To study whether Foxm1 participates in the maintenance of pluripotency of stem cells, we knock down Fo...

RNA interference (RNAi) is a key regulator of various biological systems including viral infection. Within a virus life cycle gene products can be modulated by the RNA interference (RNAi) pathway which can crucially impact productive virus replication. Herein we explored the RNA interference suppressor protein P19 derived from a plant virus and we found that P19 enhanced adenovirus replication ...

We characterized a novel protein of the Ras family, p19 (H-RasIDX). The c-H-ras proto-oncogene undergoes alternative splicing of the exon termed IDX. We show that the alternative p19 mRNA is stable and as abundant as p21 (p21 H-Ras4A) mRNA in all of the human tissues and cell lines tested. IDX is spliced into stable mRNA in different mammalian species, which present a high degree of nucleotide ...

Murine P19 embryonal carcinoma (EC) cells can be differentiated into various germ layer derivatives. The addition of retinoic acid (RA) to P19-EC cell aggregates results in a transient activation of receptor protein tyrosine phosphatase-alpha (RPTP alpha). Subsequent replating of these aggregates leads to neuronal differentiation. P19-EC cells expressing constitutively active RPTP alpha (P19-RP...

The adenovirus E1A oncogene activates p53 through a signaling pathway involving the retinoblastoma protein and the tumor suppressor p19(ARF). The ability of E1A to induce p53 and its transcriptional targets is severely compromised in ARF-null cells, which remain resistant to apoptosis following serum depletion or adriamycin treatment. Reintroduction of p19(ARF) restores p53 accumulation and res...