Eckmann CR , Jantsch MF .

	Figure 2. xlADAR1 localizes to the nascent RNP matrix and is specifically enriched on a special loop on bivalent no. 3. LBCs were prepared from oocytes expressing myc-tagged ADAR1.1. (a–d) Normal LBC and (e–f) bivalent no. 3. (a and e) DIC image, (b and f) DAPI staining, (c and g) localization of endogenous ADAR1 detected with SAT4 antiserum in the rhodamine channel and (d and h) localization of myc-tagged ADAR1.1 detected with mAb 9E10 in the fluorescein channel. Endogenous and ectopically expressed ADAR1 is localized to LBC loops. (g and h) A special loop on bivalent no. 3 is enriched for endogenous (g) and ectopically expressed ADAR1 (h). The special loop is marked by arrows. Faint background signals can be seen on nucleoli (N) or snurposomes (S) by staining with SAT4 antiserum that is not seen with myc-tagged ADAR1.1. Bar, 10 μm.
	Figure 3. Localization of ADAR1 to LBC loops is RNA dependent. Staining of bivalent no. 3 with SAT4 antiserum. (a, d, g, j, and m) DIC image, (b, e, h, k, and n) DAPI staining, and (c, f, i, l, and o) staining with Sat4 in the fluorescein channel. (a–c) ADAR1 is localized to LBC loops and is specifically enriched on a special loop. (d–f) Staining with Sat4 can be blocked by ADAR1 peptide. (f) SAT signal is almost completely diminished when the antiserum was blocked with ADAR1 peptide originally used for the immunization. (g–i) SAT staining is sensitive to RNAse treatment. LBCs were digested with RNAse before staining with Sat4 antiserum. (g) The loops appear “stripped” after RNAse treatment, and (i) no signal can be observed in the fluorescein channel. (j–l) Treatment with actinomycin D inhibits transcription and diminishes staining of regular loops but not of the special loop on bivalent no. 3. (j) DIC image of bivalent no. 3 prepared from an oocyte after incubation in AMD. The chromosomal axes is condensed and shows no transcriptionally active loops. Also nucleoli (N) change their morphology. (k) The condensed, shortened chromosomal axes is well stained with DAPI. The position of the special loop forming a “double loop bridge” is seen by the interrupted DAPI staining of the chromosomal axes on both homologues (arrowhead). (l) As transcription is inhibited no ADAR1 staining can be observed. Only the special loop is still brilliantly labeled by SAT4 antiserum. (m–o) Injection of an unrelated oligonucleotide temporarily inhibits transcription but does not affect ADAR1 localization on the special loop on bivalent no. 3. (m) DIC image of bivalent no. 3 prepared from an oocyte 24 h after injection of an oligonucleotide. The presence of loops on the chromosome indicates that transcription has already resumed. (n) DAPI image of the same region. (o) ADAR1 can be detected on most transcripts and on the special loop by staining with SAT4 antiserum. Note: Shortly after injection of the oligo transcription seizes and no ADAR1 staining can be detected on regular loops (not shown). However, staining of the brilliantly labeling loop is not affected by this treatment. Bars, 10 μm.
	Figure 4. Double staining of the special loop on bivalent no. 3 with various antibodies and SAT antiserum. (a, d, g, and j) DIC images, (b, e, h, and k) fluorescein channel, and (c, f, i, and l) staining with SAT4 antiserum in the rhodamine channel. Arrows mark the position of the special loop. (a–c) Staining with mAbH14 (b) shows the presence of RNA Pol-II on all regular loops as a fine signal seen in the center of each loop. However, Pol-II is absent from the special loop which is brilliantly labeled by SAT4 antiserum (c). (d–f) Staining with mAb K121 indicates the presence of 3mG snRNP cap structures on the special loop (e) which is also labeled with SAT4 antiserum (f). (g–i) mAb Y12 stains regular loops and the special loop indicating the presence of Sm proteins on the special loop (h). (j–l) The SR splicing factor SC35 can also be found on the special loop (k). Bar, 10 μm.
	Figure 5. Splicing is not required for ADAR1 localization. (a and d) DIC images, (b and e) DAPI staining, and (c and f) ADAR1 localization detected by staining with SAT4 antiserum in the fluorescein channel. (a–c) Staining of bivalent no. 3 from an untreated oocyte shows localization of ADAR1 on the RNP matrix of regular loops and on the special loop. (d–f) 24 h after injection of the U2b oligo transcription has resumed giving rise to prominent loops (d). (f) Staining with SAT4 antiserum shows the presence of ADAR1 on the loop matrix and on the special loop on bivalent no. 3. Bar, 10 μm.
	Figure 7. (a) Schematic representation of deletion constructs used in this study. The peptide repeats (left striped box), the ZBD (black box), the dsRBDs (right striped box) and the deamination domain (gray box) are indicated. ΔREP deletes the NH2-terminal peptide repeats from ADAR1.1 leaving a single, COOH-terminal myc tag. ΔZBD deletes a longer portion from the NH2 terminus of ADAR1.1 including the putative Z-DNA binding domain and one of two putative NLSs. ADAR1.2 does not contain the peptide repeats and is only myc-tagged at its COOH terminus. An artificial AUG codon was introduced at the beginning of the cDNA. (b) Western blot of oocyte nuclei (GV) and cytoplasms (Cytopl.) of uninjected oocytes (−) and of oocytes expressing myc-tagged ADAR1 versions. All myc-tagged ADAR1 versions express well and accumulate in the nucleus. Cytoplasmic signals are seen 24 h after injection but diminish over time as the protein is transported to the nucleus. (c) ADAR1 undergoes NH2-terminal proteolytic cleavage. Western blot of oocyte nuclei (GV) and cytoplasms (Cytopl.) of uninjected (−) or injected oocytes expressing ADAR1.1 myc tagged at its COOH terminus (C), COOH and NH2 terminus (NC) or NH2 terminus only (N). In the cytoplasm full-length versions (180 to 190 kD) of all three constructs can be easily detected (upper two arrowheads). A smaller (150 kD) breakdown product can only be detected for the two versions carrying a COOH-terminal myc-tag (lower arrowhead). In the nucleus (GV) the breakdown product is the most prominent form found 24 h after injection. However, also the full-length versions can be detected in the nucleus. If the myc-tag is only present at the NH2 terminus (N) only full-length protein can be detected, indicating that the NH2 terminus undergoes proteolytic cleavage.
	Figure 6. In situ localization of ADAR1.2 and ADAR1.1 deletions. (a, e, and i) DIC image, (b, f, and j) DAPI staining, (c, g, and k) localization of myc-tagged ADAR1 variants as seen in the fluorescein channel, and (d, h, l) localization of endogenous ADAR1 as seen after staining with SAT4 antiserum in the rhodamine channel. (a–d) myc-tagged ADAR1.2 localizes like ADAR1.1 to regular loops and to the special loop on bivalent no. 3. (c) the localization of myc-tagged ADAR1.2 and (d) endogenous protein is virtually identical. (e–h) The NH2-terminal peptide repeats found in ADAR1.1 are not required for localization of the protein. (g) myc-tagged ΔREP construct localizes to nascent transcripts and to the special loop on bivalent no. 3. (i–l) Construct ΔZBD, deleting the NH2-terminal end of ADAR1.1 including a putative Z-DNA binding domain and one putative NLS, shows wild-type-like in situ localization. (k) myc-tagged ΔZBD construct (l) counterstaining with Sat4 antiserum. Bar, 10 μm.

Bass, A developmentally regulated activity that unwinds RNA duplexes. 1987, Pubmed, Xenbase

Bass, A developmentally regulated activity that unwinds RNA duplexes. 1987, Pubmed , Xenbase
Bass, An unwinding activity that covalently modifies its double-stranded RNA substrate. 1988, Pubmed , Xenbase
Bass, RNA editing and hypermutation by adenosine deamination. 1997, Pubmed
Bass, A standardized nomenclature for adenosine deaminases that act on RNA. 1997, Pubmed
Baurén, Splicing of Balbiani ring 1 gene pre-mRNA occurs simultaneously with transcription. 1994, Pubmed
Beyer, Splice site selection, rate of splicing, and alternative splicing on nascent transcripts. 1988, Pubmed
Brooks, The double-stranded RNA-binding domains of Xenopus laevis ADAR1 exhibit different RNA-binding behaviors. 1998, Pubmed , Xenbase
Burns, Regulation of serotonin-2C receptor G-protein coupling by RNA editing. 1997, Pubmed
Cattaneo, Biased hypermutation and other genetic changes in defective measles viruses in human brain infections. 1988, Pubmed
Dabiri, Editing of the GLuR-B ion channel RNA in vitro by recombinant double-stranded RNA adenosine deaminase. 1996, Pubmed
Eckmann, Xlrbpa, a double-stranded RNA-binding protein associated with ribosomes and heterogeneous nuclear RNPs. 1997, Pubmed , Xenbase
Evan, Isolation of monoclonal antibodies specific for human c-myc proto-oncogene product. 1985, Pubmed , Xenbase
Fu, Factor required for mammalian spliceosome assembly is localized to discrete regions in the nucleus. 1990, Pubmed
Gerber, Tad1p, a yeast tRNA-specific adenosine deaminase, is related to the mammalian pre-mRNA editing enzymes ADAR1 and ADAR2. 1998, Pubmed
Herb, Q/R site editing in kainate receptor GluR5 and GluR6 pre-mRNAs requires distant intronic sequences. 1996, Pubmed
Herbert, A Z-DNA binding domain present in the human editing enzyme, double-stranded RNA adenosine deaminase. 1997, Pubmed
Higuchi, RNA editing of AMPA receptor subunit GluR-B: a base-paired intron-exon structure determines position and efficiency. 1993, Pubmed
Hough, Purification of the Xenopus laevis double-stranded RNA adenosine deaminase. 1994, Pubmed , Xenbase
Hough, Analysis of Xenopus dsRNA adenosine deaminase cDNAs reveals similarities to DNA methyltransferases. 1997, Pubmed , Xenbase
Hulsebos, Lampbrush loop-specific protein of Drosophila hydei. 1984, Pubmed
Hurst, Deamination of mammalian glutamate receptor RNA by Xenopus dsRNA adenosine deaminase: similarities to in vivo RNA editing. 1995, Pubmed , Xenbase
Jantsch, Assembly and localization of the U1-specific snRNP C protein in the amphibian oocyte. 1992, Pubmed , Xenbase
Kim, Molecular cloning of cDNA for double-stranded RNA adenosine deaminase, a candidate enzyme for nuclear RNA editing. 1994, Pubmed
Kim, Splicing factors associate with hyperphosphorylated RNA polymerase II in the absence of pre-mRNA. 1997, Pubmed
Kimelman, An antisense mRNA directs the covalent modification of the transcript encoding fibroblast growth factor in Xenopus oocytes. 1989, Pubmed , Xenbase
Krainer, Pre-mRNA splicing by complementation with purified human U1, U2, U4/U6 and U5 snRNPs. 1988, Pubmed
Lerner, Monoclonal antibodies to nucleic acid-containing cellular constituents: probes for molecular biology and autoimmune disease. 1981, Pubmed , Xenbase
Lomeli, Control of kinetic properties of AMPA receptor channels by nuclear RNA editing. 1994, Pubmed , Xenbase
Melcher, A mammalian RNA editing enzyme. 1996, Pubmed
O'Connell, Cloning of cDNAs encoding mammalian double-stranded RNA-specific adenosine deaminase. 1995, Pubmed
O'Connell, Purification of human double-stranded RNA-specific editase 1 (hRED1) involved in editing of brain glutamate receptor B pre-mRNA. 1997, Pubmed
O'Connell, RNA editing: rewriting receptors. 1997, Pubmed
Pan, Assembly of functional U1 and U2 human-amphibian hybrid snRNPs in Xenopus laevis oocytes. 1988, Pubmed , Xenbase
Patterson, Expression and regulation by interferon of a double-stranded-RNA-specific adenosine deaminase from human cells: evidence for two forms of the deaminase. 1995, Pubmed
Paul, Inosine exists in mRNA at tissue-specific levels and is most abundant in brain mRNA. 1998, Pubmed
Peculis, Localization of the nucleolar protein NO38 in amphibian oocytes. 1992, Pubmed , Xenbase
Petschek, RNA editing and alternative splicing generate mRNA transcript diversity from the Drosophila 4f-rnp locus. 1997, Pubmed
Polson, The mechanism of adenosine to inosine conversion by the double-stranded RNA unwinding/modifying activity: a high-performance liquid chromatography-mass spectrometry analysis. 1991, Pubmed
Polson, Preferential selection of adenosines for modification by double-stranded RNA adenosine deaminase. 1994, Pubmed
Polson, RNA editing of hepatitis delta virus antigenome by dsRNA-adenosine deaminase. 1996, Pubmed , Xenbase
Rebagliati, Antisense RNA injections in fertilized frog eggs reveal an RNA duplex unwinding activity. 1987, Pubmed , Xenbase
Sommer, RNA editing in brain controls a determinant of ion flow in glutamate-gated channels. 1991, Pubmed
St Johnston, A conserved double-stranded RNA-binding domain. 1992, Pubmed , Xenbase
Tsvetkov, Transcription on lampbrush chromosome loops in the absence of U2 snRNA. 1992, Pubmed , Xenbase
Vincent, The nuclear matrix protein p255 is a highly phosphorylated form of RNA polymerase II largest subunit which associates with spliceosomes. 1996, Pubmed
Visa, A nuclear cap-binding complex binds Balbiani ring pre-mRNA cotranscriptionally and accompanies the ribonucleoprotein particle during nuclear export. 1996, Pubmed
Wu, Small nuclear ribonucleoproteins and heterogeneous nuclear ribonucleoproteins in the amphibian germinal vesicle: loops, spheres, and snurposomes. 1991, Pubmed , Xenbase
Yang, Editing of glutamate receptor subunit B pre-mRNA in vitro by site-specific deamination of adenosine. 1995, Pubmed