Figure 4. MALAT1 Is Not Required for Nuclear Speckle Structural Integrity but Influences the Distribution of Splicing Factors to Nuclear Speckles.
(A and B) MALAT1 RNA-FISH in control (scr-oligo, a–a″) and MALAT1 antisense oligo-treated (48 hr post antisense treatment; b–b″) HeLa cells expressing GFP-SF1 (A) or GFP-U2AF65 (B).
(C) MALAT1 RNA-FISH and SF3a60 immunolocalization in control (Ca–Ca″) and MALAT1-depleted (Cb–Cb″) HeLa cell.
(D) YFP-SRSF1 and B″-U2snRNP immunolocalization in scr-oligo (Da–Da″) and MALAT1-depleted (Db–Db″) HeLa cell.
(E) UAP56 immunolocalization in control (Ea–Ea′) and MALAT1-depleted (Eb–Eb′) HeLa cell.
(F) RNA-FISH using oligo-dT probe in control (Fa) and MALAT1 antisense oligonucleotides-treated (Fb) HeLa cells. The bars in all the figures represent 10 μm.
(G) RNA slot blot using oligo dT probe in control (scr-oligo) and MALAT1 antisense oligonucleotide-treated (AS1) HeLa cell nuclear (nuc) and cytoplasmic (cyto) extracts showed increased levels of cytoplasmic poly(A)+ RNA upon MALAT1 depletion (fold change, MALAT1 AS1/scr 100 ng = 0.63; 250 ng = 1.36; 500 ng = 1.6). See also Figure S4. The asterisk represents poly(A)+ RNA from control cells.