A promoter element that exerts positive and negative control of the interleukin 2-responsive J-chain gene.

Lansford, Rusty; McFadden, Helen J; Siu, Shirley T.; Cox, Jeffery S.; Cann, Gordon M.; Koshland, Marian Elliott

doi:10.1073/pnas.89.13.5966

Cited by 29 publications

(30 citation statements)

References 28 publications

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“…The evidence was based on gel mobility shift assays showing that substitutions in bases in contact with PU. 1 abolished the formation of a single band corresponding to a PU.1 monomer-probe complex and left other more slowly migrating bands intact (Lansford et al 1992). Further evidence that only a single species of PU.1 binds the JB element was obtained by comparing the binding patterns of endogenous PU.1 to JB and K3' enhancer probes {Fig.…”

Section: Pu1 Binds the Jb Element Only As A Monomermentioning

confidence: 92%

“…1 was previously assigned an activator role in J-chain gene transcription based on mutational analyses of the JB element (Lansford et al 1992). This assignment was suppurine-rich JB element with relatively high affinity, despite the fact that the element lacks the GGA core.…”

Section: Pu1 Trans-activation Of the J-chain Jb Promoter Elementmentioning

confidence: 99%

“…Reporter plasmids were constructed by inserting four copies of wild-type or mutant JB oligonucleotide in the J21 vector upstream of a minimal c-los promoter and the CAT gene (Lenardo et al 1987). Although the c-los-linked system was less sensitive to JB regulation than the ~-fibrinogen linked system used in previous analyses (Lansford et al 1992), it had the advantage of a detectable basal chloramphenicol acetyltransferase (CAT) activity in both J-chain-negative and J-chain-positive cells and, thus, allowed comparison of the results from the different lines. Various combinations of the reporter and effector plasmids were then transfected into HeLa cells that lack PU.…”

Section: Genes and Development 2009mentioning

confidence: 99%

“…The choice of amino-terminal truncations was based on earlier studies that had delineated three structural features of the protein: an acidic amino-terminal sequence (residues 1-118) presumed to encode an activation domain, a basic carboxy-terminal sequence known to contain the DNAbinding domain (167-255), and a connecting PEST sequence (119-160) that has been implicated as a site of protein-protein interaction (Klemsz et al 1990;Pongubala et al 1992Pongubala et al , 1993. The effect of the deletions was then measured by transfecting the expression plasmids into S 194 cells along with a reporter plasmid containing four copies of the JB-binding sites upstream of a minimal 7-fibrinogen promoter and the CAT gene (Lansford et al 1992).…”

Section: Identification Of Pu1 Activation Domainmentioning

confidence: 99%

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Ets-related protein PU.1 regulates expression of the immunoglobulin J-chain gene through a novel Ets-binding element.

Shin

Koshland²

1993

Genes Dev.

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126

108

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A c/s-acting negative regulator of splicing (NRS) within the gag gene of RSV is involved in control of the relative levels of spliced and unspliced viral mRNAs. Insertion of the NRS into the intron of an adenovirus pre-mRNA resulted in inhibition of splicing in vitro before the first cleavage step. Analyses of spliceosome assembly with this substrate showed that it formed large RNP complexes that did not migrate like mature spliceosomes on native gels. Affinity selection of the RNP complexes formed on NRS-containing pre-mRNAs showed an association with U l l and U12 snRNPs, as well as with the spliceosomal snRNPs. Immunoprecipitation with antisera specific for U1 and U2 snRNPS showed binding of both snRNPs to NRS RNA. A 7-nucleotide missense mutation in the NRS that prevented binding of U l l and U12 snRNPs impaired NRS activity in vivo, suggesting a functional role for U l l and U12 snRNPS in the inhibition of splicing mediated by the RSV NRS RNA.[Key Words: Retrovirus; RNA splicing; snRNPs] Received June 23, 1993; revised version accepted July 28, 1993.Retroviral replication involves reverse transcription of the RNA genome into DNA, which integrates into the host genome and is transcribed by cellular RNA polymerase II (for review, see Coffin 1990). While the viral RNA transcripts are processed, transported, and translated by cellular machinery, they yield both spliced and unspliced cytoplasmic mRNAs, unlike cellular premRNAs. The majority of the viral transcripts are not spliced but are transported to the cytoplasm, where they become full-length mRNA for Gag and Gag-Pol polyproteins, as well as packaged virion RNA. In the case of Rous sarcoma virus (RSV), the remainder of the primary transcripts are alternatively spliced in the nucleus to yield mRNAs for the env and src gene products. Production of infectious virus requires a balance of spliced and unspliced mRNAs.Splicing of mRNA precursors occurs in a dynamic macromolecular complex called a spliceosome; the reaction requires ATP, functional splice site and branchpoint sequences, small nuclear ribonucleoproteins (snRNPs), heterogeneous ribonucleoproteins (hnRNPs), and essential non-snRNP splicing factors (for review, see Krainer and Maniatis 1988; Green 1991). The spliceosomal snRNP particles U1, U2, U4/U6, and U5 are abundant in animal cells (10s-10 6 copies per cell) and participate in both steps of pre-mRNA splicing (for review, see Steitz et al. 1988). Genetic experiments have confirmed the sig- nificance of RNA-RNA base-pairing between U1 snRNA and the 5' splice site (Zhuang and Weiner 1986) and U2 snRNA and the branchpoint (Wu and Manley 1989; Zhuang and Weiner 1989). The U4/U6 and U5 snRNPs, which appear to associate as a multi-snRNP complex (Konarska and Sharp 1987), have also been identified as components of the mature spliceosome (Frendewey and Keller 1985; Bindereif and Green 1987). Other less abundant snRNPs have been identified whose functions have not been defined (Kramer 1987; Reddy and Busch 1988). For example, Wassarman and Steitz (1992...

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Section: Pu1 Binds the Jb Element Only As A Monomermentioning

confidence: 92%

Section: Pu1 Trans-activation Of the J-chain Jb Promoter Elementmentioning

confidence: 99%

Section: Genes and Development 2009mentioning

confidence: 99%

Section: Identification Of Pu1 Activation Domainmentioning

confidence: 99%

See 2 more Smart Citations

Ets-related protein PU.1 regulates expression of the immunoglobulin J-chain gene through a novel Ets-binding element.

Shin

Koshland²

1993

Genes Dev.

Self Cite

126

108

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“…A complete J-chain cDNA flanked byXba I restriction sites was synthesized from MxW231 RNA by reverse transcription-PCR (10). The cDNA was ligated into pSVL (Pharmacia LKB) at theXba I site, a neomycin-resistance gene (from pMClneo; Stratagene) at the EcoRI site, and the , heavy-chain intron enhancer (Eli) at the Sal I site.…”

Section: Methodsmentioning

confidence: 99%

Polymer IgM assembly and secretion in lymphoid and nonlymphoid cell lines: evidence that J chain is required for pentamer IgM synthesis.

Niles

Matsuuchi

Koshland

1995

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

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The requirements for IgM assembly and secretion were evaluated by introducing a constitutively expressed J-chain cDNA into lymphoid and nonlymphoid cell lines expressing the secretory form of monomer IgM. Assays of cell lysates and supernatants showed that only secretory monomer IgM is required for the synthesis and secretion of hexamer IgM, whereas J chain, as well as the secreted form of monomer, is required for the synthesis and secretion of pentamer IgM. Moreover, J chain facilitates the polymerization process so that pentamer IgM is preferentially synthesized. Other components of the polymerization process were found to be shared by all the cell lines examined, whether the cells were of lymphoid or nonlymphoid origin and had a rudimentary or developed secretory apparatus. These results identify monomer IgM and J chain as the two components that determine the B-cell-specific expression of IgM antibodies and, thus, as the appropriate targets for therapeutic regulation of IgM responses.In a primary immune response, a resting B cell is triggered by antigen and successive cytokine signals to differentiate into a blast cell that secretes pentamer IgM antibody. Analyses of the response have identified the de novo synthesis of the pentamer joining protein, the J chain, as a critical step in the differentiative process (1). The evidence is based in part on structural studies which revealed that J chain is incorporated exclusively into the pentameric form of IgM (2). Within the pentamer it links two monomer subunits through disulfide bonds between cysteines at positions 14 and 68 of the J chain and the penultimate cysteines of opposing p. heavy chains (3, 4).Evidence for the role of J chain is also based on the responses of B-cell lines to J-chain gene expression. B lymphomas expressing receptors for interleukin 2 or 5 can be induced by cytokine treatment to amplify J-chain gene transcription and, as a consequence, to markedly increase secretion of IgM (5-7). Moreover, B-cell lymphoma lines can be converted to IgM secretors by transfection with a J-chain cDNA (2) or by fusion with an IgG-secreting myeloma that expresses the J chain (8, 9).Although the expression of J chain correlates strongly with pentamer IgM synthesis, several questions remain concerning the actual function of the J polypeptide in the polymerization process. First, is J chain required for pentamer assembly, or does it simply facilitate closing of the polymer at the pentamer stage? Second, does the expression of J chain in turn induce changes in other B-cell components that contribute to IgM assembly and secretion? These questions were addressed in the present study by transfecting the murine J-chain cDNA into a series of B lymphomas representing successive stages in B-cell differentiation and transfecting all three pentamer components into a nonlymphoid cell line. Here we present evidence that (i) J chain is required for the synthesis of the pentamer, but not the hexamer form of IgM, (ii) its expression is regulated independently of the oth...

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Mucosal Immune Defense

Kaetzel¹

Encyclopedic Reference of Cancer

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A promoter element that exerts positive and negative control of the interleukin 2-responsive J-chain gene.

Cited by 29 publications

References 28 publications

Ets-related protein PU.1 regulates expression of the immunoglobulin J-chain gene through a novel Ets-binding element.

Ets-related protein PU.1 regulates expression of the immunoglobulin J-chain gene through a novel Ets-binding element.

Polymer IgM assembly and secretion in lymphoid and nonlymphoid cell lines: evidence that J chain is required for pentamer IgM synthesis.

Mucosal Immune Defense

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