Ask about this productRelated genes to: SAP30BP antibody
- Gene:
- SAP30BP NIH gene
- Name:
- SAP30 binding protein
- Previous symbol:
- -
- Synonyms:
- HCNGP, HTRG, HTRP
- Chromosome:
- 17q25.1
- Locus Type:
- gene with protein product
- Date approved:
- 2006-01-05
- Date modifiied:
- 2014-11-19
Related products to: SAP30BP antibody
Related articles to: SAP30BP antibody
- The cyclin-dependent kinase CDK11 functions in transcription, mitotic progression, and mRNA splicing. Specifically, spliceosome activation during the B to B transition depends on phosphorylation of the U2 snRNP component SF3B1 by the CDK11-cyclin L-SAP30BP complex. Here, we present the structure of this spliceosome-activating CDK-cyclin complex, determined by cryogenic electron microscopy at 2.3 Å resolution. Our structure and biochemical experiments show that SAP30BP forms extensive interactions with cyclin L2, thereby stabilising it, and forms critical interactions with the C-terminal kinase lobe of CDK11 that promote complex assembly. Destabilisation of cyclin L2 in the absence of SAP30BP suggests that these principles are applicable to all CDK11-cyclin L complexes. Furthermore, we identify a pseudo-substrate sequence near the CDK11 C-terminus and provide evidence for a role of this segment in CDK11 auto-regulation. Finally, the structure of the CDK11-cyclin L-SAP30BP complex bound to the clinical high-affinity CDK11 inhibitor OTS964 and a comparison to OTS964-bound off-target complexes provide insight into the mechanism of OTS964 selectivity and specificity. - Source: PubMed
Publication date: 2026/04/25
McGeoch Amy J SCushing Victoria IRoumeliotis Theodoros ICronin Nora BHearnshaw Stephen JChoudhary Jyoti SAlfieri ClaudioGreber Basil J - Cyclin-dependent kinase 11 (CDK11) is essential for the regulation of pre-mRNA splicing via phosphorylation of the core spliceosome component SF3B1. This phosphorylation is a marker of the catalytically active spliceosomes; thus, it is important to identify the mechanisms that regulate CDK11 itself. Here, we report that a small subset of CDK11 is phosphorylated on the activation T-loop threonine 595 (Thr595) and is associated with the activated spliceosome on chromatin in gene bodies. Mutational analyses revealed that Thr595 is essential for the formation of the active CDK11 complex with cyclin L and SAP30BP. CDK11 transiently associates with CDK7, a transcriptional kinase that also promotes the activation of other CDKs. Inhibition of CDK7 initially decreases transcription, but longer durations of inhibition lead to production of unspliced pre-mRNAs. The onset of the CDK7-mediated splicing defect correlates with the sequential dephosphorylation of CDK11 Thr595 and SF3B1. SILAC-based phosphoproteomics upon brief CDK11 inhibition identified SF3B1, CDC5L, and ESS2 as CDK11 substrates, which overlap with the previously identified CDK7 substrates in the spliceosome. In summary, our study suggests that CDK7 likely acts via CDK11 Thr595 phosphorylation to regulate pre-mRNA splicing in cells. The identification of additional CDK11 substrates points to its broader role in spliceosome regulation. - Source: PubMed
Rájecký MichalGajdušková PavlaManík PeterHluchý MilanHegedűsová EvaKryštofová KarolínaPotěšil DavidMartinková PetraSlabá ZuzanaKhirsariya PrashantŠebesta MarekParuch KamilFriedel Caroline CZdráhal ZbyněkBlazek Dalibor - Ferroptosis is characterized by iron overload and uncontrolled lipid peroxidation, which plays a substantial role in the development of diabetic cardiomyopathy (DCM). However, the exact factor responsible for inducing ferroptosis in DCM has not been fully elucidated. SAP30 binding protein (SAP30BP), a member of the HCNGP family, functions as a transcription regulator. Our research reveals a significant increase in SAP30BP expression in the hearts of DCM mice and cardiomyocytes treated with high glucose (HG). Knockdown of SAP30BP ameliorated cardiac dysfunction and inhibited ferroptosis and mitochondrial damage in DCM hearts. At the cellular levels, transfection of si-SAP30BP suppressed ferroptosis, as evidenced by the reduced oxidative stress, iron overload and lipid peroxidation. RNA-seq and GEO database analysis suggested that mitochondrial dynamics contributed to SAP30BP induced ferroptosis. Mechanistically, SAP30BP inhibited the transcription of MFN2 through HDAC1-mediated histone deacetylation, leading to mitochondrial dynamic disruption and dysfunction. This process ultimately hindered the mitochondrial translocation of ACSL4 and mitochondria-associated ferroptosis. Collectively, our findings demonstrate the therapeutic benefits of SAP30BP knockdown in DCM by effectively suppressing mitochondria-associated ferroptosis through the MFN2-ACSL4 pathway. These results provide new mechanistic insights and a basis for developing mitochondria and ferroptosis targeting therapies for DCM. - Source: PubMed
Publication date: 2025/08/06
Zhao TongChen ChenZhao WenjieHan JingjingOmar Jan MohammadLou HanChen ZhouxiuLiu XinJing Shenhong - SAP18 protein was originally discovered in association with the SIN3 transcriptional repressor complex. Subsequent biochemical fractionation studies identified SAP18 as a component of another distinct trimeric complex termed as the apoptosis- and splicing-associated protein (ASAP) complex. The existence of SAP18 in distinct complexes highlights its dual role in transcriptional and splicing regulation. In our study, we aim to define the in vivo interactome of SAP18 using proximity-dependent biotin identification (BioID). Mass spectrometry analysis of streptavidin-purified biotinylated proteins revealed new SIN3-associated interactors, including RBBP4 and SAP30BP. Notably, we identified 72 spliceosomal proteins as highly enriched interactors. Additionally, a complementary immunoprecipitation assay validated novel interactions of SAP18 with the prespliceosomal components SNRNP70, SNRPA, SF3B1, U2AF1, and the SR protein SRSF1. Mutational analysis using a C-terminal SAP18 double point mutant, which is known to be deficient in ASAP-interaction, demonstrated a debilitated interaction with the prespliceosomal proteins. Altogether, our results present a refined understanding of the SAP18 interactome, uncovering its association with the prespliceosome in conjugation with ASAP components. - Source: PubMed
Publication date: 2024/11/01
Kumari SwetaAdhikary AnkitaSingh Kusum Kumari - Human pre-mRNA splicing requires the removal of introns with highly variable lengths, from tens to over a million nucleotides. Therefore, mechanisms of intron recognition and splicing are likely not universal. Recently, we reported that splicing in a subset of human short introns with truncated polypyrimidine tracts depends on RBM17 (SPF45), instead of the canonical splicing factor U2 auxiliary factor (U2AF) heterodimer. Here, we demonstrate that SAP30BP, a factor previously implicated in transcriptional control, is an essential splicing cofactor for RBM17. In vitro binding and nuclear magnetic resonance analyses demonstrate that a U2AF-homology motif (UHM) in RBM17 binds directly to a newly identified UHM-ligand motif in SAP30BP. We show that this RBM17-SAP30BP interaction is required to specifically recruit RBM17 to phosphorylated SF3B1 (SF3b155), a U2 small nuclear ribonucleoprotein (U2 snRNP) component in active spliceosomes. We propose a mechanism for splicing in a subset of short introns, in which SAP30BP guides RBM17 in the assembly of active spliceosomes. - Source: PubMed
Publication date: 2023/12/07
Fukumura KazuhiroSperotto LucaSeuß StefanieKang Hyun-SeoYoshimoto ReiSattler MichaelMayeda Akila