Virus and nuclear structures affect

Virus and nuclear structures affecting cell cycle
Viruses also target nuclear bodies inducing modifications in
these nuclear substructures, including promyelocytic leukemia bodies, Cajal bodies, and nucleoli. The nucleolus is the
best studied nuclear body to be described as a target of viral
subversion of host cell cycle regulation. This nuclear body
is formed around rRNA genes and has as its primary
function ribosome biogenesis (Boisvert et al. 2007). The
most abundant nucleolar proteins are nucleolin and B23,
also called nucleophosmin, and these are involved in many
functions. Recent studies reveal that nucleoli contain
multifunctional proteins that play many roles in different
cellular pathways (Andersen et al. 2005). There is a
concurrent growth in the knowledge of nucleolus protein
function and its relevance in viral infection. A recent
publication has shown that nucleolin is required for
efficient nuclear egress of HSV-1 nucleocapsids, although
the mechanism by which nucleolin acts remain to be
determined (Sagou et al.2010).
Infection with HSV-1 results in dramatic alterations to
nuclear structure and organization, including changes in the
morphology of nucleoli (Besse and Puvion-Dutilleul1996).
In cells infected with HSV-1, staining for nucleolin reveals
a diffuse distribution throughout the nucleus, in contrast to
the large, prominent spots of nucleolin observed within the
nucleus of mock-infected cells. During infection with HSV-1, UL24 family gene homologues are detected predominantly in the nucleus and transiently localize in the nucleoli
(Hong-Yan et al. 2001; Nascimento and Parkhouse 2007;
Pearson and Coen 2002;Wangetal.2000, 2004).
Expression of the N-terminal domain of UL24 is sufficient
to induce the redistribution of nucleolin in the nucleus
(Bertrand et al. 2010; Bertrand and Pearson 2008).
However, cells infected with two independent UL24-deficient viruses, UL24XB and UL24XG, retain the
prominent foci of nucleolin staining, although the pattern
was not identical to the uninfected cells. This result
indicates that this alteration of the nucleoli in HSV-1-infected cells is partially dependent on UL24 (Lymberopoulos et al. 2011). The fact that deletion of UL24
conserved homology domains, including the putative
endonuclease motifs, resulted in loss of nucleolin and B23
dispersal activity suggests that this function may be shared
among all herpesviruses and must be relevant for the viral
life cycle (Bertrand et al. 2010; Bertrand and Pearson 2008;
Lymberopoulos et al.2011). Indeed, a study with UL24
homologues from human herpesviruses representative of
each subfamily (HSV-1 UL24, HCMV UL76, and KSHV
ORF20) showed that all these genes are able to induce cell
cycle arrest followed by apoptosis. Expression of UL24
homologues results in an increase in Cdc2 phosphorylation
increase at the Tyr-15 inactivation site and consequent
inhibition of the mitotic complex cdc2–cyclin B (Nascimento
et al.2009). The mechanism by which this cell cycle arrest is
induced or if the nucleolin is involved in this phenotype is not
described. Extensive reviews on viral proteins impacting on
nucleolus have been published. In conclusion, the multifunctionality of virus host evasion genes may provide
important tools to unravel the complex interactions underlying
the regulation of intracellular signaling.
Acknowledgment The authors thank the“Fundação para a Ciencia
e a Tecnologia”, SFRH/BPD/34643/2007 (Nascimento R.), SFRH/
BD/27677/2006 (Costa H.).

Results (Indonesian) 1:

Virus and nuclear structures affecting cell cycleViruses also target nuclear bodies inducing modifications inthese nuclear substructures, including promyelocytic leukemia bodies, Cajal bodies, and nucleoli. The nucleolus is thebest studied nuclear body to be described as a target of viralsubversion of host cell cycle regulation. This nuclear bodyis formed around rRNA genes and has as its primaryfunction ribosome biogenesis (Boisvert et al. 2007). Themost abundant nucleolar proteins are nucleolin and B23,also called nucleophosmin, and these are involved in manyfunctions. Recent studies reveal that nucleoli containmultifunctional proteins that play many roles in differentcellular pathways (Andersen et al. 2005). There is aconcurrent growth in the knowledge of nucleolus proteinfunction and its relevance in viral infection. A recentpublication has shown that nucleolin is required forefficient nuclear egress of HSV-1 nucleocapsids, althoughthe mechanism by which nucleolin acts remain to bedetermined (Sagou et al.2010).Infection with HSV-1 results in dramatic alterations tonuclear structure and organization, including changes in themorphology of nucleoli (Besse and Puvion-Dutilleul1996).In cells infected with HSV-1, staining for nucleolin revealsa diffuse distribution throughout the nucleus, in contrast tothe large, prominent spots of nucleolin observed within thenucleus of mock-infected cells. During infection with HSV-1, UL24 family gene homologues are detected predominantly in the nucleus and transiently localize in the nucleoli(Hong-Yan et al. 2001; Nascimento and Parkhouse 2007;Pearson and Coen 2002;Wangetal.2000, 2004).Expression of the N-terminal domain of UL24 is sufficientto induce the redistribution of nucleolin in the nucleus(Bertrand et al. 2010; Bertrand and Pearson 2008).However, cells infected with two independent UL24-deficient viruses, UL24XB and UL24XG, retain theprominent foci of nucleolin staining, although the patternwas not identical to the uninfected cells. This resultindicates that this alteration of the nucleoli in HSV-1-infected cells is partially dependent on UL24 (Lymberopoulos et al. 2011). The fact that deletion of UL24conserved homology domains, including the putativeendonuclease motifs, resulted in loss of nucleolin and B23dispersal activity suggests that this function may be sharedamong all herpesviruses and must be relevant for the virallife cycle (Bertrand et al. 2010; Bertrand and Pearson 2008;Lymberopoulos et al.2011). Indeed, a study with UL24homologues from human herpesviruses representative ofeach subfamily (HSV-1 UL24, HCMV UL76, and KSHVORF20) showed that all these genes are able to induce cellcycle arrest followed by apoptosis. Expression of UL24homologues results in an increase in Cdc2 phosphorylationmeningkatkan Tyr-15 inaktivasi situs dan konsekueninhibisi mitosis kompleks cdc2 – siklin b (Nascimentoet al.2009). Mekanisme dengan mana penangkapan siklus sel ini adalahdiinduksi dan atau jika nucleolin terlibat dalam fenotipe ini bukanlahdijelaskan. Luas review tentang protein viral berdampak padanucleolus telah diterbitkan. Kesimpulannya, multifunctionality host penghindaran gen virus dapat memberikanalat penting untuk mengungkap kompleks interaksi yang mendasariPeraturan signaling intraseluler.Pengakuan penulis Terima "Fundação para a Cienciae Tecnologia ", SFRH/BPD/34643/2007 (Nascimento R.), SFRH /BD/27677/2006 (Costa H.).

Results (Indonesian) 2:

Virus dan nuklir struktur yang mempengaruhi siklus sel
Virus juga menargetkan badan nuklir menginduksi modifikasi di
substruktur nuklir ini, termasuk badan promyelocytic leukemia, tubuh Cajal, dan nukleolus. Nukleolus adalah
tubuh nuklir terbaik dipelajari untuk digambarkan sebagai target virus
subversi regulasi siklus sel inang. Tubuh nuklir ini
terbentuk sekitar gen rRNA dan memiliki sebagai yang utama
fungsi ribosom Biogenesis (Boisvert et al. 2007). The
protein nukleolus yang paling banyak adalah nucleolin dan B23,
juga disebut nucleophosmin, dan ini terlibat dalam banyak
fungsi. Penelitian terbaru mengungkapkan bahwa nukleolus mengandung
protein multifungsi yang memainkan banyak peran di berbagai
jalur seluler (Andersen et al. 2005). Ada
pertumbuhan bersamaan dalam pengetahuan protein nucleolus
fungsi dan relevansinya dalam infeksi virus. Baru-baru ini
publikasi telah menunjukkan bahwa nucleolin diperlukan untuk
egress nuklir efisien HSV-1 nukleokapsid, meskipun
mekanisme yang bertindak nucleolin tetap harus
ditentukan (Sagou et al.2010).
Infeksi HSV-1 hasil perubahan dramatis untuk
struktur nuklir dan organisasi, termasuk perubahan dalam
morfologi nukleolus (Besse dan Puvion-Dutilleul1996).
Dalam sel yang terinfeksi dengan HSV-1, pewarnaan untuk nucleolin mengungkapkan
distribusi menyebar di seluruh inti, berbeda dengan
besar, bintik-bintik menonjol dari nucleolin diamati dalam
inti sel mock-terinfeksi. Selama infeksi dengan HSV-1, UL24 homolog gen keluarga terdeteksi terutama di inti dan transiently melokalisasi dalam nukleolus
(Hong-Yan et al 2001;. Nascimento dan Parkhouse 2007;
Pearson dan Coen 2002; Wangetal.2000, 2004).
Ekspresi dari domain N-terminal dari UL24 cukup
untuk menginduksi redistribusi nucleolin dalam inti
(Bertrand et al 2010;. Bertrand dan Pearson 2008).
Namun, sel yang terinfeksi dengan dua UL24-kekurangan virus independen, UL24XB dan UL24XG, mempertahankan
fokus menonjol dari pewarnaan nucleolin, meskipun pola
itu tidak identik dengan sel-sel yang tidak terinfeksi. Hasil ini
menunjukkan bahwa perubahan ini dari nukleolus dalam sel HSV-1-terinfeksi sebagian tergantung pada UL24 (Lymberopoulos et al. 2011). Fakta bahwa penghapusan UL24
dilestarikan domain homologi, termasuk diduga
motif endonuklease, mengakibatkan hilangnya nucleolin dan B23
aktivitas penyebaran menunjukkan bahwa fungsi ini dapat dibagi
di antara semua virus herpes dan harus relevan untuk virus
siklus hidup (Bertrand et al. 2010 ; Bertrand dan Pearson 2008;
Lymberopoulos et al.2011). Memang, sebuah penelitian dengan UL24
homolog dari virus herpes manusia perwakilan dari
masing-masing subfamili (HSV-1 UL24, HCMV UL76, dan KSHV
ORF20) menunjukkan bahwa semua gen ini mampu menginduksi sel
penangkapan siklus diikuti dengan apoptosis. Ekspresi UL24
homolog menghasilkan peningkatan Cdc2 fosforilasi
peningkatan di lokasi inaktivasi Tyr-15 dan konsekuen
penghambatan mitosis kompleks Cdc2-cyclin B (Nascimento
et al.2009). Mekanisme yang sel penangkapan siklus ini
disebabkan atau jika nucleolin yang terlibat dalam fenotip ini tidak
dijelaskan. Ulasan ekstensif pada protein virus yang berdampak pada
nucleolus telah diterbitkan. Kesimpulannya, multifungsi gen penggelapan virus tuan rumah dapat memberikan
alat penting untuk mengungkap interaksi kompleks yang mendasari
regulasi sinyal intraseluler.
Pengakuan Para penulis mengucapkan terima kasih kepada "Fundação para a Ciencia
ea Tecnologia", SFRH / BPD / 34643/2007 (Nascimento R .), SFRH /
BD / 27677/2006 (Costa H.).