Table 1.
Major proposed functions of mRNA nuclear export factors
| NPC-mediated pathways | |||
|---|---|---|---|
| Metazoan | Yeast (S. cerevisiae) | Role | References |
| NXF1-mediated pathway | |||
| NXF1 (TAP) | Mex67 | Major transport receptor for mRNA export |
[19, 20] |
| NXT1 (p15) | Mtr2 | mRNA export factor, binds to NXF1 to form heterodimeric complex |
[82, 83] |
| REF/Aly | Yra1 | Forms part of a complex that binds export-competent mRNPs |
[23–25] |
| CRM1-mediated pathway | |||
| CRM1 | Xpo1 | Major export receptor for proteins and some specific mRNAs |
[17, 18] |
| NXF3 | Tissue specific adaptor for CRM1 |
[51] | |
| pp32 (ANP32a) | Adaptor for CRM1, interacts with HuR |
[50] | |
| APRIL (ANP32b) | Adaptor for CRM1, interacts with HuR |
[50] | |
| HuR | Adaptor for CRM1 binds to AU-rich elements in 3’UTR |
[50] | |
| hCG1 | Nup42 | FG-Nup localized to cytoplasmic face; required for heat shock mRNA export |
[71–73] |
| Gle1 | Gle1 | Export factor that binds to hCG1; involved in mRNP remodeling by activating Dbp5; binds inositol hexakisphosphate (IP6) |
[36, 37, 72, 84] |
| Nup214 | Nup159 | FG-Nup localized to cytoplasmic face; triggers ADP release from Dbp5 |
[39, 41, 85, 86] |
| DDX19 | Dbp5 | RNA-dependent DEAD-box ATPase; involved in mRNP remodeling; ATPase cycle regulated by a by Gle1-IP6 and Nup159 |
[38, 39, 87] |
| Nup358/RanBP2 | Major component of NPC cytoplasmic filaments; potential role in CRM1- mediated export |
[44, 88] | |
| NE budding-mediated pathways | |||
| aPKC | Phosphorylates and remodels nuclear lamins |
[14] | |
| DFrizzled2 | Wnt-1 receptor whose cleavage product, DFz2C, localizes to intranuclear foci |
[89, 90] | |
| LamC | Nuclear lamin protein, required for localization of RNA granules to perinuclear space |
[14] | |