RPB7, one of two dissociable subunits of yeast RNA polymerase II, is essential for cell viability

McKune, Keith; Richards, Kristy L.; Edwards, A.M.; Young, Richard A.; Woychik, Nancy A.

doi:10.1002/yea.320090309

Cited by 79 publications

(63 citation statements)

References 24 publications

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“…Second, Rpb4 (Kimura et al, 2001) and Rpb7 (Khazak et al, 1995;Na et al, 2003) can be found in the cytoplasm with Rpb4 mediating RNA export from the nucleus under stress conditions (Farago et al, 2003) and both Rpb4 and Rpb7 are involved in selective mRNA decay (Lotan et al, 2005;Goler-Baron et al, 2008). In terms of their biological roles, while scRpb4 and scRpb7 may not be identical (scRpb4 is conditional (Woychik and Young, 1989) and scRpb7 is essential (McKune et al, 1993)) both proteins are nonetheless involved in particular stress responses (Choder and Young, 1993;Sheffer et al, 1999;Maillet et al, 1999;Pillai et al, 2001) and are implicated in morphological changes that accompany nutrient starvation (Khazak et al, 1995;Pillai et al, 2003). Consistent with the conditional nature of scRpb4, global gene expression profiling in yeast indicates that a limited number of genes (~2% of the genome) are affected by Rpb4 (Pillai et al, 2003), although other evidence points to a more global effect (Miyao et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

The RNA Pol II sub-complex hsRpb4/7 is required for viability of multiple human cell lines

Zhao¹,

Li²,

Ng³

et al. 2012

Protein Cell

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The evolutionarily conserved RNA Polymerase II Rpb4/7 sub-complex has been thoroughly studied in yeast and impacts gene expression at multiple levels including transcription, mRNA processing and decay. In addition Rpb4/7 exerts differential effects on gene expression in yeast and Rpb4 is not obligatory for yeast (S. cerevisiae) survival. Specialised roles for human (hs) Rpb4/7 have not been extensively described and we have probed this question by depleting hsRpb4/7 in established human cell lines using RNA interference. We find that Rpb4/7 protein levels are inter-dependent and accordingly, the functional effects of depleting either protein are co-incident. hsRpb4/7 exhibits gene-specific effects and cells initially remain viable upon hsRpb4/7 depletion. However prolonged hsRpb4/7 depletion is cytotoxic in the range of cell lines tested. Protracted cell death occurs by an unknown mechanism and in some cases is accompanied by a pronounced elongated cell morphology. In conclusion we provide evidence for a gene-specific role of hsRpb4/7 in human cell viability.

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Section: Introductionmentioning

confidence: 99%

The RNA Pol II sub-complex hsRpb4/7 is required for viability of multiple human cell lines

Zhao¹,

Li²,

Ng³

et al. 2012

Protein Cell

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“…35 Surface plasmon resonance studies demonstrated that the yeast RPB7 protein together with RPB4 stabilizes a pre-initiation complex consisting of promoter DNA, TATA box-binding protein, transcription factor TFIIB, as well as the RNA polymerase II being responsible for mRNA generation as a prerequisite for protein translation. 36 Only recently the existence of an evolutionarily conserved human homologue to RPB7 was shown, ie, hsRPB7.…”

Section: Discussionmentioning

confidence: 99%

Suprabasal Overexpression of the hsRPB7 Gene in Psoriatic Epidermis as Identified by a Reverse Transcriptase-Polymerase Chain Reaction Differential Display Model Comparing Psoriasis Plaque Tissue with Peritonsillar Mucosa

Böckelmann

Neugebauer

Paseban

et al. 2001

The American Journal of Pathology

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In psoriasis an etiopathogenetic vicious circle is nowadays hypothesized that the disease is triggered by skin-specific autoantigen structures, the expression and accessibility of which are positively correlated with the intensity of the hyperproliferation and inflammation in the epidermopapillary compartment driven by autoreactive T cells. Despite the close microanatomical relation between skin and mucosa, clinicians have always been intrigued by the observation that psoriatic affection of the mucosa, if at all existing, is only seen as very rare events in the lips and tongue sparing buccopharyngeal sites. This prompted us to establish an experimental model system comparing psoriatic-involved skin and peritonsillar mucosa from tonsillectomies by a reverse transcriptase-polymerase chain reaction/differential display strategy. Among more than 60 cDNA species to be displayed in psoriasis, but missing in peritonsillar mucosa, one species was identified as coding for the RNA polymerase IIA seventh subunit (hsRPB7 gene) as a most critical factor for DNA to RNA transcription. Immunohistochemistry showed a hitherto unknown, distinctive pattern of hsRPB7 expression that was 1) tissue type-dependent with a surplus in skin keratinocytes and a near absence in peritonsillar mucosa, 2) tightly regulated by the keratinocyte differentiation process with a sharp suprabasal up-regulation in contrast to a basal down-regulation, and 3) substantially augmented in psoriatic-involved skin as compared to normal and psoriatic uninvolved skin. Keratinocytes of actinic keratoses also showed a strong hsRPB7 expression that however did not strictly spare the basal cell layer presumably reflecting the disturbed intraepidermal stratification because of the premalignant status of these precancerous lesions. The etiology of psoriasis is still unknown.

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“…Rpb7 is essential for survival of Saccharomyces cerevisiae, whereas Rpb4 is not (5). However, rpb4⌬ strains are temperature-sensitive and cold-sensitive, show poor recovery from stationary phase, are defective in sporulation (a response to severe nutritional starvation), and are predisposed to pseudohyphae formation (a response to mild nutritional starvation) (4).…”

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Unstructured N Terminus of the RNA Polymerase II Subunit Rpb4 Contributes to the Interaction of Rpb4·Rpb7 Subcomplex with the Core RNA Polymerase II of Saccharomyces cerevisiae

Sampath

Balakrishnan

Verma-Gaur

et al. 2008

Journal of Biological Chemistry

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Two subunits of eukaryotic RNA polymerase II, Rpb7 and Rpb4, form a subcomplex that has counterparts in RNA polymerases I and III. Although a medium resolution structure has been solved for the 12-subunit RNA polymerase II, the relative contributions of the contact regions between the subcomplex and the core polymerase and the consequences of disrupting them have not been studied in detail. We have identified mutations in the N-terminal ribonucleoprotein-like domain of Saccharomyces cerevisiae Rpb7 that affect its role in certain stress responses, such as growth at high temperature and sporulation. These mutations increase the dependence of Rpb7 on Rpb4 for interaction with the rest of the polymerase. Complementation analysis and RNA polymerase pulldown assays reveal that the Rpb4⅐Rbp7 subcomplex associates with the rest of the core RNA polymerase II through two crucial interaction points: one at the N-terminal ribonucleoprotein-like domain of Rpb7 and the other at the partially ordered N-terminal region of Rpb4. These findings are in agreement with the crystal structure of the 12-subunit polymerase. We show here that the weak interaction predicted for the N-terminal region of Rpb4 with Rpb2 in the crystal structure actually plays a significant role in interaction of the subcomplex with the core in vivo. Our mutant analysis also suggests that Rpb7 plays an essential role in the cell through its ability to interact with the rest of the polymerase.Studies of transcriptional regulation have focused mainly on the role of DNA-bound regulatory proteins and their contacts with the general transcription factors, mediator, and other accessory proteins in the transcriptional machinery. In most eukaryotes, the 12-subunit RNA polymerase II (Pol II) 4 is thought to have little or no influence on the regulation of transcription. Rpb4 and Rpb7 form a subcomplex within the polymerase that dissociates easily under mild denaturing or nondenaturing conditions and shows variable association with the polymerase at different growth stages, leading to the suggestion that the subcomplex could be analogous to the subunit of the bacterial RNA polymerase (1-3). Whether such a regulatory role can be ascribed to the subcomplex has been a matter of some debate, but the phenotypes of the deletion mutants and the interactions mediated by these subunits suggest that they might have some regulatory role in stress response and transcription (4).Rpb7 is essential for survival of Saccharomyces cerevisiae, whereas Rpb4 is not (5). However, rpb4⌬ strains are temperature-sensitive and cold-sensitive, show poor recovery from stationary phase, are defective in sporulation (a response to severe nutritional starvation), and are predisposed to pseudohyphae formation (a response to mild nutritional starvation) (4). Apart from its roles in stress response, Rpb4 is involved in transcription under moderate and extreme temperatures (6). The polymerase lacking Rpb4 and Rpb7 is defective for promoter-dependent initiation of transcription but not for promoter-inde...

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RPB7, one of two dissociable subunits of yeast RNA polymerase II, is essential for cell viability

Cited by 79 publications

References 24 publications

The RNA Pol II sub-complex hsRpb4/7 is required for viability of multiple human cell lines

The RNA Pol II sub-complex hsRpb4/7 is required for viability of multiple human cell lines

Suprabasal Overexpression of the hsRPB7 Gene in Psoriatic Epidermis as Identified by a Reverse Transcriptase-Polymerase Chain Reaction Differential Display Model Comparing Psoriasis Plaque Tissue with Peritonsillar Mucosa

Unstructured N Terminus of the RNA Polymerase II Subunit Rpb4 Contributes to the Interaction of Rpb4·Rpb7 Subcomplex with the Core RNA Polymerase II of Saccharomyces cerevisiae

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