Overview
| Uniprot ID | Q9Z1N5 |
|---|
| Protein Name | Spliceosome RNA helicase Ddx39b |
|---|
| Gene Name | Ddx39b |
|---|
| Organism | Mus musculus |
|---|
Kla Sites from experimental identification
| Position |
Flanking peptide |
| 36 |
APAKKDVKGSYVSIH |
Function
Involved in nuclear export of spliced and unspliced mRNA. Component of the TREX complex which is thought to couple mRNA transcription, processing and nuclear export, and specifically associates with spliced mRNA and not with unspliced pre-mRNA. The TREX complex is recruited to spliced mRNAs by a transcription-independent mechanism, binds to mRNA upstream of the exon-junction complex (EJC) and is recruited in a splicing- and cap-dependent manner to a region near the 5' end of the mRNA where it functions in mRNA export to the cytoplasm via the TAP/NXF1 pathway. The THOC1-THOC2-THOC3 core complex alone is sufficient to promote ATPase activity of DDX39B; in the complex THOC2 is the only component that directly interacts with DDX39B. Associates with SARNP/CIP29, which facilitates RNA binding of DDX39B and likely plays a role in mRNA export. May undergo several rounds of ATP hydrolysis during assembly of TREX to drive subsequent loading of components such as ALYREF/THOC4 and CHTOP onto mRNA. Also associates with pre-mRNA independent of ALYREF/THOC4. Involved in the nuclear export of intronless mRNA; the ATP-bound form is proposed to recruit export adapter ALYREF/THOC4 to intronless mRNA; its ATPase activity is cooperatively stimulated by RNA and ALYREF/THOC4 and ATP hydrolysis is thought to trigger the dissociation from RNA to allow the association of ALYREF/THOC4 and the NXF1-NXT1 heterodimer. Involved in transcription elongation and genome stability
Protein Sequence
10
MAENDVDNEL
20
LDYEDDEVET
30
AAGADGTEAP
40
AKKDVKGSYV
50
SIHSSGFRDF
60
LLKPELLRAI
70
VDCGFEHPSE
80
VQHECIPQAI
90
LGMDVLCQAK
100
SGMGKTAVFV
110
LATLQQLEPV
120
TGQVSVLVMC
130
HTRELAFQIS
140
KEYERFSKYM
150
PNVKVAVFFG
160
GLSIKKDEEV
170
LKKNCPHIVV
180
GTPGRILALA
190
RNKSLNLKHI
200
KHFILDECDK
210
MLEQLDMRRD
220
VQEIFRMTPH
230
EKQVMMFSAT
240
LSKEIRPVCR
250
KFMQDPMEIF
260
VDDETKLTLH
270
GLQQYYVKLK
280
DNEKNRKLFD
290
LLDVLEFNQV
300
VIFVKSVQRC
310
IALAQLLVEQ
320
NFPAIAIHRG
330
MPQEERLSRY
340
QQFKDFQRRI
350
LVATNLFGRG
360
MDIERVNIAF
370
NYDMPEDSDT
380
YLHRVARAGR
390
FGTKGLAITF
400
VSDENDAKIL
410
NDVQDRFEVN
420
ISELPDEIDI
SSYIEQTR
Gene Ontology
| Classification |
GO ID |
Description |
| Cellular Component |
GO:0005737 |
cytoplasm |
| Cellular Component |
GO:0016363 |
nuclear matrix |
| Cellular Component |
GO:0016607 |
nuclear speck |
| Cellular Component |
GO:0005634 |
nucleus |
| Cellular Component |
GO:0032991 |
protein-containing complex |
| Cellular Component |
GO:0005681 |
spliceosomal complex |
| Cellular Component |
GO:0000346 |
transcription export complex |
| Cellular Component |
GO:0005687 |
U4 snRNP |
| Cellular Component |
GO:0005688 |
U6 snRNP |
| Molecular Function |
GO:0005524 |
ATP binding |
| Molecular Function |
GO:0016887 |
ATP hydrolysis activity |
| Molecular Function |
GO:0008186 |
ATP-dependent activity, acting on RNA |
| Molecular Function |
GO:0043008 |
ATP-dependent protein binding |
| Molecular Function |
GO:0042802 |
identical protein binding |
| Molecular Function |
GO:0003729 |
mRNA binding |
| Molecular Function |
GO:0044877 |
protein-containing complex binding |
| Molecular Function |
GO:0003724 |
RNA helicase activity |
| Molecular Function |
GO:0030621 |
U4 snRNA binding |
| Molecular Function |
GO:0017070 |
U6 snRNA binding |
| Biological Process |
GO:0006406 |
mRNA export from nucleus |
| Biological Process |
GO:0000398 |
mRNA splicing, via spliceosome |
| Biological Process |
GO:0061051 |
positive regulation of cell growth involved in cardiac muscle cell development |
| Biological Process |
GO:2000573 |
positive regulation of DNA biosynthetic process |
| Biological Process |
GO:0045727 |
positive regulation of translation |
| Biological Process |
GO:1904707 |
positive regulation of vascular associated smooth muscle cell proliferation |
| Biological Process |
GO:0008380 |
RNA splicing |
| Biological Process |
GO:0000245 |
spliceosomal complex assembly |
Reference
[1] Wu D, Tang Y, Li X, Xiong S, Zhang Z et al.. Characterization of protein lactylation in healthy and ischemic mouse hearts.. Front Cardiovasc Med 12:1644886. 2025. PMID: 41089239.