Journal: Nucleic Acids Research
Article Title: Human histone pre-mRNA assembles histone or canonical mRNA-processing complexes by overlapping 3′-end sequence elements
doi: 10.1093/nar/gkac878
Figure Lengend Snippet: The integrity of the PAS sequence in H2AC18 is essential for the assembly of the canonical 3′-pre-mRNA-processing complex. ( A ) Assembly scheme of the canonical complex on the H2A_4m RNA: in purple is depicted the hPSF module (CPSF73, CPSF100 and SYMPK), mediating PAS recognition in the RNA sequence; elements predicted as not directly involved in the interaction (HDE* and other complex modules) are depicted in gray; a sequence alignment among H2A_4m, its double mutant GA-H2A and the mouse RNA mH2A* is reported below; in the H2A_4m sequence, the PAS is indicated in purple, mutated residues in 38G/40-H2A_4m are underlined and HDEs are indicated in green. ( B ) Western blot analysis of samples purified with H2A_4m bait RNA, in the absence or presence of PAS-containing control RNAs; the use of these molecules allowed blocking, in a selective manner, of the assembly on H2A_4m of the entire canonical complex via the hPSF module (scheme on the right). ( C–E ) Comparison by western blot of processing factor abundances in samples purified with different RNAs/conditions: H2A_4m versus GA-H2A (C), GA-H2A versus mouse RNA mH2A* (D) and GA-H2A in the absence or presence of aU7/SL RNAs (E); mutations in GA-H2A RNA disrupting the PAS sequence prevent the assembly of the entire canonical complex via the hPSF module (scheme below). In (B) and (E), the lanes separated by a black line come from different zones of the same membrane. In (C), nucleolin is used as a control protein to demonstrate the specificity of the PAS disruption effect on proteins belonging to the canonical mRNA-processing complex. Exposure time in (E) was increased, compared with (D), to better show the difference between samples without or with aU7 + SL ( F ) Western blot analyses with four antibodies of a sample purified with GA-H2A, DTSSP-cross-linked after elution from streptavidin–agarose beads and run in native PAGE. ( G ) Differential analysis of protein abundances in [H2A_4m] versus [GA-H2A] samples; relevant identified proteins that are at least 2-fold more abundant in [H2A_4m] samples compared with [GA-H2A] samples are annotated in the zoom-in graphs (subpanel on the left); a schematic representation of complex relative abundance is shown (lower subpanel). Abbreviations: CFIm, cleavage factor 1m module (including NUDT21, CPSF6 and CPSF7 subunits); CPSF, cleavage and polyadenylation specificity factor; CstF, cleavage-stimulating factor module (including CSTF1, CSTF2, CSTF2T and CSTF3 subunits); FLASH, FLICE-associated huge protein; HCC/hCF, histone cleavage complex (SYMPK, CPSF100 and CPSF73 subunits)/human cleavage factor; hPSF, human polyadenylation specificity factor (including CPSF30, CPSF160, WDR33 and FIP1 subunits); PPase, phosphatase module (including SSU72, WDR82 and PP1CA/B/C/R10 subunits).
Article Snippet: Lsm11(26119-1-AP) and Nucleolin (10556-1-AP) rabbit primary antibodies were purchased from Proteintech.
Techniques: Sequencing, Mutagenesis, Western Blot, Purification, Control, Blocking Assay, Comparison, Membrane, Disruption, Clear Native PAGE