Translation Initiation on Mammalian mRNAs with Structured 5′UTRs Requires DExH-Box Protein DHX29

Pisareva, Vera P.; Pisarev, Andrey V.; Komar, Anton A.; Hellen, Christopher U.T.; Pestova, Tatyana V.

doi:10.1016/j.cell.2008.10.037

Cited by 211 publications

(285 citation statements)

References 37 publications

Supporting

Mentioning

275

Contrasting

Order By: Relevance

“…More recent studies have confirmed that eIFs 2/3/1/1A/4A/4B/4F are sufficient to promote efficient 48S complex formation on ␤-globin mRNA and on model synthetic mRNAs with minimally structured 5ЈUTRs (5,7,33). The use of mRNAs with minimally structured 5ЈUTRs in previous biochemical assays is most likely the reason why DHX29 was identified only very recently.…”

Section: Discussionmentioning

confidence: 99%

“…DHX29 has been found to interact with the 40S ribosomal subunit in vitro and to associate with 40S ribosomal complexes in a rabbit reticulocyte lysate (7). To determine how general these findings are, we examined the distribution of DHX29 in polysome preparations from HeLa cells using 2 commercial DHX29 antibodies (Fig.…”

Section: Dhx29 Is a Ubiquitously Expressed Cytoplasmic Protein That Amentioning

confidence: 99%

“…DHX29 plays a prominent role in the translation of mRNAs with highly structured 5ЈUTRs (7). The addition of DHX29 to an in vitro reconstituted translation system strongly stimulated 48S complex formation on mRNAs containing stable secondary structures in their 5ЈUTRs, such as Cdc25C mRNA (⌬G ϭ Ϫ85 kcal/mol) (7).…”

Section: Dhx29 Is Required For Translation Initiation On Mrnas With Smentioning

confidence: 99%

“…Thus, in addition to its role in the initial attachment of ribosomal complexes to mRNA, eIF4A is believed to assist ribosomal complexes during scanning (5). Recent observations suggest that the process of eukaryotic initiation requires additional members of the DEAD/DExH-box protein family; for instance, a DEAD-box protein, yeast Ded1, and its mammalian homologue, DDX3, are biochemically and genetically implicated in translation initiation on long structured 5ЈUTRs (6), and another DExH-box protein, DHX29, strongly stimulates cap-dependent initiation on mRNAs with structured 5ЈUTRs in vitro (7). Here we studied the importance of DHX29 for translation in vivo and characterized it as a novel factor required for cell proliferation.…”

mentioning

confidence: 99%

See 3 more Smart Citations

The helicase protein DHX29 promotes translation initiation, cell proliferation, and tumorigenesis

Parsyan

Shahbazian²,

Martineau³

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

103

104

View full text Add to dashboard Cite

Translational control plays an important role in cell growth and tumorigenesis. Cap-dependent translation initiation of mammalian mRNAs with structured 5 UTRs requires the DExH-box protein, DHX29, in vitro. Here we show that DHX29 is important for translation in vivo. Down-regulation of DHX29 leads to impaired translation, resulting in disassembly of polysomes and accumulation of mRNA-free 80S monomers. DHX29 depletion also impedes cancer cell growth in culture and in xenografts. Thus, DHX29 is a bona fide translation initiation factor that potentially can be exploited as a target to inhibit cancer cell growth.I nitiation is a tightly regulated rate-limiting step in the translation of eukaryotic mRNAs. Ribosome recruitment to the mRNA commences with binding of translation initiation factor 4F (eIF4F) to the 7-methyl guanosine cap structure, which is present at the 5Ј end of all nuclear-encoded eukaryotic mRNAs (1). eIF4F (comprising the cap-binding protein eIF4E, the DEAD-box RNA helicase eIF4A and eIF4G, a scaffold for binding eIF4E and eIF4A) binds to the cap, unwinds (with the aid of eIF4A) the cap-proximal region of the mRNA, and, through interaction with the ribosome-bound eIF3, recruits the 40S ribosomal subunit to the mRNA (2-4). The 40S subunit then scans the 5Ј UTR in a 5Ј to 3Ј direction until it encounters an initiation codon. A subsequent joining of the 60S ribosomal subunit and release of eIFs result in formation of an elongationcompetent 80S ribosome.Secondary structures in 5ЈUTRs of mRNAs are thought to become unwound to allow ribosomal complexes to move along the mRNA in search of the initiation codon. Thus, in addition to its role in the initial attachment of ribosomal complexes to mRNA, eIF4A is believed to assist ribosomal complexes during scanning (5). Recent observations suggest that the process of eukaryotic initiation requires additional members of the DEAD/DExH-box protein family; for instance, a DEAD-box protein, yeast Ded1, and its mammalian homologue, DDX3, are biochemically and genetically implicated in translation initiation on long structured 5ЈUTRs (6), and another DExH-box protein, DHX29, strongly stimulates cap-dependent initiation on mRNAs with structured 5ЈUTRs in vitro (7). Here we studied the importance of DHX29 for translation in vivo and characterized it as a novel factor required for cell proliferation. Results DHX29 Is a Ubiquitously Expressed Cytoplasmic Protein That Associ-ates with the 40S Ribosomal Subunit. DHX29 has been found to interact with the 40S ribosomal subunit in vitro and to associate with 40S ribosomal complexes in a rabbit reticulocyte lysate (7). To determine how general these findings are, we examined the distribution of DHX29 in polysome preparations from HeLa cells using 2 commercial DHX29 antibodies (Fig. 1A). The specificity of these antibodies to human DHX29 was confirmed by immunoblotting against the purified native protein [supporting information (SI) Fig. S1] and recombinant DHX29, as well as by the loss of immunoreactivity following DHX29 RNAi ...

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Dhx29 Is a Ubiquitously Expressed Cytoplasmic Protein That Amentioning

confidence: 99%

Section: Dhx29 Is Required For Translation Initiation On Mrnas With Smentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

The helicase protein DHX29 promotes translation initiation, cell proliferation, and tumorigenesis

Parsyan

Shahbazian²,

Martineau³

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

103

104

View full text Add to dashboard Cite

show abstract

“…But the unwinding of such structures by eIF4A during translation initiation has not been shown directly, and eIF4A-independent scanning has been seen 95 . Moreover, the DEAD box protein Ded1 and the non-DEAD box protein DEAH box 29 (DHX29) affect translation of mRNAs with long and structured 5′ UTRs, respectively 96,97 . One alternative, and not mutually exclusive, possibility is that eIF4A induces conformational changes in the translation initiation complex, or that ATPmodulated, transient bindin g to RNA may be necessary for ordered initiation to occur 92 .…”

Section: Nuclear Specklesmentioning

confidence: 99%

From unwinding to clamping — the DEAD box RNA helicase family

Linder

Jankowsky

2011

Nat Rev Mol Cell Biol

918

1,069

View full text Add to dashboard Cite

Nearly all aspects of RNA metabolism, from transcription and translation to mRNA decay, involve RNA helicases, which are enzymes that use ATP to bind or remodel RNA and RNA-protein complexes (ribonucleoprotein (RNP) complexes) 1 . RNA helicases are found in all three domains of life, and many viruses also encode one or more of these proteins 2,3 . Together with the structurally related DNA helicases that function in replication, recombination and repair, the RNA helicases are classified into superfamilies and families, based on sequence and structural features 3,4 . DEAD box proteins form the largest helicase family, with 37 members in humans and 26 in Saccharomyces cerevisiae 3 , and are characterized by the presence of an Asp-Glu-Ala-Asp (DEAD) motif.DEAD box helicases have central and, in many cases, essential physiological roles in cellular RNA metabolism 5 (FIG. 1). The proteins generally function as part of larger multicomponent assemblies, such as the spliceosom e or the eukaryotic translation initiation machinery 6 . Mutations and deregulation of several DEAD box proteins have been linked to disease states, including cancer 7 . Although all DEAD box proteins contain a structurally highly conserved core with conserved ATP-binding and RNA-binding sites, different proteins have been associated with diverse and seemingly unrelated functions, including the disassembly of RNPs, chaperoning during RNA folding and even stabil ization of protein complexes on RNA 5,6 . How these highly conserved proteins fulfil such an array of different functions has been a long-standing question.Research has now started to illuminate the molecular basis for this functional diversity. In this Review, we summarize how structural data, together with biochemical and biophysical studies, have revealed unexpected modes by which these proteins function. We also discuss how novel molecular and cell biological approaches have better defined the cellular roles of DEAD box helicases. We outline our current view on common structural and mechan istic themes that have emerged, and on physical models of how these 'unusual' RNA helicases work.Structures of DEAD box RNA helicases A number of structural studies have universally shown that members of the DEAD box family contain a highly conserved helicase core that harbours the binding sites for ATP and RNA 3,4,8 . The core is surrounded by variable auxiliary domains, which are thought to be critical for the diverse functions of these enzymes.Structure of the helicase core. DEAD box proteins belong to helicase superfamily 2 (SF2) 2 . Similarly to all SF2 helicases, DEAD box proteins are built around a highly conserved helicase core of two virtually identical domains that resemble the bacterial recombination protein recombinase A (RecA) 3,4,8 (FIG. 2a,b). Within this helicase core, at least 12 characteristic sequence motifs are located at conserved positions (FIG. 2a,b). Some of these motifs are conserved across the entire SF2 family, whereas others are found only in the DEAD box family 3 ....

show abstract

Definition of 5q11.2 microdeletion syndrome reveals overlap with CHARGE syndrome and 22q11 deletion syndrome phenotypes

Blok

Corsten‐Janssen

FitzPatrick

et al. 2014

American J of Med Genetics Pt A

View full text Add to dashboard Cite

Microdeletions of the 5q11.2 region are rare; in literature only two patients with a deletion in this region have been reported so far. In this study, we describe four additional patients and further define this new 5q11.2 microdeletion syndrome. A comparison of the features observed in all six patients with overlapping 5q11.2 deletions showed a phenotypic spectrum that overlaps with CHARGE syndrome and 22q11.2 deletion syndrome including choanal atresia, developmental delay, heart defects, external ear abnormalities, and short stature. No colobomas or abnormalities of semicircular canals and olfactory nerves were reported. Two male patients had genital abnormalities. We estimated a 2.0 Mb (53.0-55.0 Mb) Shortest Region of Overlap (SRO) for the main clinical characteristics of the syndrome. This region contains nine genes and two non-coding microRNAs. In this region DHX29 serves as the candidate gene as it encodes an ATP-dependent RNA-helicase that is involved in the initiation of RNA translation. Screening a small cohort of 14 patients who presented the main features, however, did not reveal any pathogenic abnormalities of DHX29.

show abstract

Translation Initiation on Mammalian mRNAs with Structured 5′UTRs Requires DExH-Box Protein DHX29

Cited by 211 publications

References 37 publications

The helicase protein DHX29 promotes translation initiation, cell proliferation, and tumorigenesis

The helicase protein DHX29 promotes translation initiation, cell proliferation, and tumorigenesis

From unwinding to clamping — the DEAD box RNA helicase family

Definition of 5q11.2 microdeletion syndrome reveals overlap with CHARGE syndrome and 22q11 deletion syndrome phenotypes

Contact Info

Product

Resources

About