Interaction of the porcine reproductive and respiratory syndrome virus nucleocapsid protein with the inhibitor of MyoD family-a domain-containing protein

2009 ◽  
Vol 390 (3) ◽  
Author(s):  
Cheng Song ◽  
Ray Lu ◽  
Dorothee Bienzle ◽  
Hsiao-Ching Liu ◽  
Dongwan Yoo
Keyword(s):  
Transcription Factor ◽  
Cultured Cells ◽  
Specific Interaction ◽  
Respiratory Syndrome Virus ◽  
N Protein ◽  
Prrs Virus ◽  
Cellular Transcription Factor ◽  
Cellular Transcription ◽  
Two Hybrid

AbstractPorcine reproductive and respiratory syndrome (PRRS) virus is an RNA virus that replicates in the cytoplasm, but the viral nucleocapsid (N) protein localizes specifically in the nucleus and nucleolus of virus-infected cells. Nuclear localization of N is non-essential for PRRSV replication in cultured cells but has been shown to modulate the pathogenesis of virus in pigs, suggesting that N plays an accessory role in the nucleus during infection. We identified by yeast two-hybrid screening the inhibitor of MyoD family-a (I-mfa) domain-containing protein (HIC) as a cellular partner for PRRS virus (PRRSV) N protein. This protein is a homolog of human HIC, a recently identified cellular transcription factor. The specific interaction of PRRSV N with HIC was confirmed in cells by mammalian two-hybrid assay and co-immunoprecipitation andin vitroby GST pull-down assay. HIC is a zinc-binding protein and confocal microscopy demonstrated co-localization of N with the HIC-p40 isomer in the nucleus and nucleolus, and in the cytoplasm with HIC-p32, which is the N-terminal truncation of HIC-p40. The porcine homolog of HIC is universally expressed in pig tissues including alveolar macrophages. The interaction of viral capsid with the cellular transcription factor implicates a possible regulation of host cell gene expression by the N protein during PRRSV infection.

scholarly journals Downregulation of vaccinia virus intermediate and late promoters by host transcription factor YY1

2009 ◽  
Vol 90 (7) ◽  
pp. 1592-1599 ◽  
Author(s):  
Bruce A. Knutson ◽  
Jaewook Oh ◽  
Steven S. Broyles
Keyword(s):  
Transcription Factor ◽  
Vaccinia Virus ◽  
Transcriptional Repression ◽  
Late Gene ◽  
Viral Promoter ◽  
Cellular Transcription Factor ◽  
Transcriptional Promoters ◽  
Transcription Factor Yy1 ◽  
Cellular Transcription

Approximately half of the intermediate and late gene transcriptional promoters of vaccinia virus have a binding site for the cellular transcription factor YY1 that overlaps the initiator elements. Depletion of YY1 using RNA interference enhanced the activity of these promoters, while overexpression of YY1 repressed their activity. Viral promoter nucleotide replacements that specifically impair the binding of YY1 mostly alleviated the transcriptional repression and correlated with the ability of YY1 to stably interact with the initiator DNAs in vitro. The transcriptional repression activity was localized to the C-terminal DNA-binding domain of the protein. These results indicate that YY1 functions to negatively regulate these vaccinia virus promoters by binding to their initiator elements.

scholarly journals Structural comparison of CD163 SRCR5 from different species sheds some light on its involvement in porcine reproductive and respiratory syndrome virus-2 infection in vitro

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Hongfang Ma ◽  
Rui Li ◽  
Longguang Jiang ◽  
Songlin Qiao ◽  
Xin-xin Chen ◽  
...  
Keyword(s):  
Scavenger Receptor ◽  
Host Cells ◽  
Respiratory Syndrome Virus ◽  
Swine Industry ◽  
Prrs Virus ◽  
Rich Domain ◽  
Serious Disease ◽  
The One ◽  
And Control

AbstractPorcine reproductive and respiratory syndrome (PRRS) is a serious disease burdening global swine industry. Infection by its etiological agent, PRRS virus (PRRSV), shows a highly restricted tropism of host cells and has been demonstrated to be mediated by an essential scavenger receptor (SR) CD163. CD163 fifth SR cysteine-rich domain (SRCR5) is further proven to play a crucial role during viral infection. Despite intense research, the involvement of CD163 SRCR5 in PRRSV infection remains to be elucidated. In the current study, we prepared recombinant monkey CD163 (moCD163) SRCR5 and human CD163-like homolog (hCD163L1) SRCR8, and determined their crystal structures. After comparison with the previously reported crystal structure of porcine CD163 (pCD163) SRCR5, these structures showed almost identical structural folds but significantly different surface electrostatic potentials. Based on these differences, we carried out mutational research to identify that the charged residue at position 534 in association with the one at position 561 were important for PRRSV-2 infection in vitro. Altogether the current work sheds some light on CD163-mediated PRRSV-2 infection and deepens our understanding of the viral pathogenesis, which will provide clues for prevention and control of PRRS.

scholarly journals trans-dominant mutants of E1A provide genetic evidence that the zinc finger of the trans-activating domain binds a transcription factor.

1991 ◽  
Vol 11 (9) ◽  
pp. 4287-4296 ◽  
Author(s):  
L C Webster ◽  
R P Ricciardi
Keyword(s):  
Transcription Factor ◽  
Zinc Finger ◽  
Cellular Protein ◽  
Site Directed Mutagenesis ◽  
Cellular Transcription Factor ◽  
Dominant Phenotype ◽  
Cellular Genes ◽  
Critical Residue ◽  
The Individual ◽  
Cellular Transcription

The 289R E1A protein of adenovirus stimulates transcription of early viral and certain cellular genes. trans-Activation requires residues 140 to 188, which encompass a zinc finger. Several studies have indicated that trans-activation by E1A is mediated through cellular transcription factors. In particular, the ability of the trans-dominant E1A point mutant hr5 (Ser-185 to Asn) to inhibit wild-type E1A trans-activation was proposed to result from the sequestration of a cellular factor. Using site-directed mutagenesis, we individually replaced every residue within and flanking the trans-activating domain with a conservative amino acid, revealing 16 critical residues. Six of the individual substitutions lying in a contiguous stretch C terminal to the zinc finger (carboxyl region183-188) imparted a trans-dominant phenotype. trans-Dominance was even produced by deletion of the entire carboxyl region183-188. Conversely, an intact finger region147-177 was absolutely required for trans-dominance, since second-site substitution of every critical residue in this region abrogated the trans-dominant phenotype of the hr5 protein. These data indicate that the finger region147-177 bind a limiting cellular transcription factor and that the carboxyl region183-188 provides a separate and essential function. In addition, we show that four negatively charged residues within the trans-activating domain do not comprise a distinct acidic activating region. We present a model in which the trans-activating domain of E1A binds to two different cellular protein targets through the finger and carboxyl regions.

scholarly journals ELAPOR1 is a secretory granule maturation-promoting factor that is lost during paligenosis

2021 ◽  
Author(s):  
Charles J. Cho ◽  
Dongkook Park ◽  
Jason C. Mills
Keyword(s):  
Transcription Factor ◽  
Secretory Granule ◽  
Cultured Cells ◽  
Tissue Injury ◽  
Pancreatic Acinar Cells ◽  
Secretory Cells ◽  
Spectrometric Analysis ◽  
Granule Maturation

A single transcription factor, MIST1 (BHLHA15), maximizes secretory function in diverse secretory cells (like pancreatic acinar cells) by transcriptionally upregulating genes that elaborate secretory architecture. Here, we show that the scantly-studied MIST1 target, ELAPOR1, is an evolutionarily conserved, novel Mannose-6-phosphate receptor (M6PR) domain-containing protein. ELAPOR1 expression was specific to zymogenic cells (ZCs, the MIST1-expressing population in the stomach). ELAPOR1 expression was lost as tissue injury caused ZCs to undergo paligenosis (ie, to become metaplastic and reenter the cell cycle). In cultured cells, ELAPOR1 trafficked with cis-Golgi resident proteins and with the trans-Golgi and late endosome protein: cation-independent M6PR. Secretory vesicle trafficking was disrupted by expression of ELAPOR1 truncation mutants. Mass spectrometric analysis of co-immunoprecipitated proteins showed ELAPOR1 and CI-M6PR shared many binding partners. However, CI-M6PR and ELAPOR1 must function differently, as CI-M6PR co-immunoprecipitated more lysosomal proteins and was not decreased during paligenosis in vivo. We generated Elapor1−/− mice to determine ELAPOR1 function in vivo. Consistent with in vitro findings, secretory granule maturation was defective in Elapor1−/− ZCs. Our results identify a role for ELAPOR1 in secretory granule maturation and help clarify how a single transcription factor maintains mature exocrine cell architecture in homeostasis and helps dismantles it during paligenosis.

trans-dominant mutants of E1A provide genetic evidence that the zinc finger of the trans-activating domain binds a transcription factor

1991 ◽  
Vol 11 (9) ◽  
pp. 4287-4296
Author(s):  
L C Webster ◽  
R P Ricciardi
Keyword(s):  
Transcription Factor ◽  
Zinc Finger ◽  
Cellular Protein ◽  
Site Directed Mutagenesis ◽  
Cellular Transcription Factor ◽  
Dominant Phenotype ◽  
Cellular Genes ◽  
Critical Residue ◽  
The Individual ◽  
Cellular Transcription

The 289R E1A protein of adenovirus stimulates transcription of early viral and certain cellular genes. trans-Activation requires residues 140 to 188, which encompass a zinc finger. Several studies have indicated that trans-activation by E1A is mediated through cellular transcription factors. In particular, the ability of the trans-dominant E1A point mutant hr5 (Ser-185 to Asn) to inhibit wild-type E1A trans-activation was proposed to result from the sequestration of a cellular factor. Using site-directed mutagenesis, we individually replaced every residue within and flanking the trans-activating domain with a conservative amino acid, revealing 16 critical residues. Six of the individual substitutions lying in a contiguous stretch C terminal to the zinc finger (carboxyl region183-188) imparted a trans-dominant phenotype. trans-Dominance was even produced by deletion of the entire carboxyl region183-188. Conversely, an intact finger region147-177 was absolutely required for trans-dominance, since second-site substitution of every critical residue in this region abrogated the trans-dominant phenotype of the hr5 protein. These data indicate that the finger region147-177 bind a limiting cellular transcription factor and that the carboxyl region183-188 provides a separate and essential function. In addition, we show that four negatively charged residues within the trans-activating domain do not comprise a distinct acidic activating region. We present a model in which the trans-activating domain of E1A binds to two different cellular protein targets through the finger and carboxyl regions.

E1A-mediated activation of the adenovirus E4 promoter can occur independently of the cellular transcription factor E4F

1991 ◽  
Vol 11 (9) ◽  
pp. 4297-4305
Author(s):  
C Jones ◽  
K A Lee
Keyword(s):  
Transcription Factor ◽  
Hela Cells ◽  
Transcriptional Activation ◽  
Promoter Activity ◽  
Core Motif ◽  
Cellular Transcription Factor ◽  
The Core ◽  
Cellular Factors

The cellular factors E4F and ATF-2 (a member of the activating transcription factor [ATF] family) bind to common sites in the adenovirus E4 promoter and have both been suggested to mediate transcriptional activation by the viral E1A protein. To assess the role of E4F, we have introduced mutations into the E4F/ATF binding sites of the E4 promoter and monitored promoter activity in HeLa cells. We find that the core motif (TGACG) of the E4F/ATF binding site is important for E4 promoter activity. However, a point mutation adjacent to the core motif that reduces E4F binding (but has no effect on ATF binding) has no effect on E4 promoter activity. Together with previous results, these findings indicate that there are at least two cellular factors (a member of the ATF family and E4F) that can function with E1A to induce transcription of the E4 promoter. We also find that certain mutations strongly reduce E4 transcription in vivo but have no effect on ATF-2 binding in vitro. These results are therefore incompatible with the possibility that (with respect to members of the ATF family) ATF-2 alone can function with E1A to transactivate the E4 promoter in HeLa cells.

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