EMD-14806
Structure of an endogenous human TREX complex bound to mRNA, map B
EMD-14806
Single-particle5.5 Å
Deposition: 21/04/2022Map released: 19/04/2023
Last modified: 03/05/2023
Sample Organism:
Homo sapiens
Sample: endogenous human TREX-mRNA complex
Deposition Authors: Pacheco-Fiallos FB
,
Vorlaender MK ,
Plaschka C
Sample: endogenous human TREX-mRNA complex
Deposition Authors: Pacheco-Fiallos FB
,
Vorlaender MK ,
Plaschka C
mRNA recognition and packaging by the human transcription-export complex.
Pacheco-Fiallos B,
Vorlander MK ,
Riabov-Bassat D,
Fin L,
O'Reilly FJ,
Ayala FI,
Schellhaas U ,
Rappsilber J ,
Plaschka C
(2023) Nature , 616 , 828 - 835
,
Riabov-Bassat D,
Fin L,
O'Reilly FJ,
Ayala FI,
Schellhaas U ,
Rappsilber J ,
Plaschka C
(2023) Nature , 616 , 828 - 835
Abstract:
Newly made mRNAs are processed and packaged into mature ribonucleoprotein complexes (mRNPs) and are recognized by the essential transcription-export complex (TREX) for nuclear export1,2. However, the mechanisms of mRNP recognition and three-dimensional mRNP organization are poorly understood3. Here we report cryo-electron microscopy and tomography structures of reconstituted and endogenous human mRNPs bound to the 2-MDa TREX complex. We show that mRNPs are recognized through multivalent interactions between the TREX subunit ALYREF and mRNP-bound exon junction complexes. Exon junction complexes can multimerize through ALYREF, which suggests a mechanism for mRNP organization. Endogenous mRNPs form compact globules that are coated by multiple TREX complexes. These results reveal how TREX may simultaneously recognize, compact and protect mRNAs to promote their packaging for nuclear export. The organization of mRNP globules provides a framework to understand how mRNP architecture facilitates mRNA biogenesis and export.
Newly made mRNAs are processed and packaged into mature ribonucleoprotein complexes (mRNPs) and are recognized by the essential transcription-export complex (TREX) for nuclear export1,2. However, the mechanisms of mRNP recognition and three-dimensional mRNP organization are poorly understood3. Here we report cryo-electron microscopy and tomography structures of reconstituted and endogenous human mRNPs bound to the 2-MDa TREX complex. We show that mRNPs are recognized through multivalent interactions between the TREX subunit ALYREF and mRNP-bound exon junction complexes. Exon junction complexes can multimerize through ALYREF, which suggests a mechanism for mRNP organization. Endogenous mRNPs form compact globules that are coated by multiple TREX complexes. These results reveal how TREX may simultaneously recognize, compact and protect mRNAs to promote their packaging for nuclear export. The organization of mRNP globules provides a framework to understand how mRNP architecture facilitates mRNA biogenesis and export.