MBNL1

Muscleblind Like Splicing Regulator 1 (MBNL1) is an RNA splicing protein that in humans is encoded by the MBNL1 gene.^[5][6][7] It has a well characterized role in Myotonic dystrophy where impaired splicing disrupts muscle development and function.^[8] In addition to regulating mRNA maturation of hundreds of genes MBNL1 (along with its paralogs MBNL2 & MBNL3) autoregulate alternative splicing of the MBNL1 pre-mRNA transcript.^[9] The founding member of the human MBNL family of proteins was the Drosophila Muscleblind protein (PMID 9334280).

MBNL1
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 3D2N, 3D2Q, 3D2S
Identifiers
Aliases	MBNL1, EXP, EXP35, EXP40, EXP42, MBNL, muscleblind like splicing regulator 1
External IDs	OMIM: 606516; MGI: 1928482; HomoloGene: 23186; GeneCards: MBNL1; OMA:MBNL1 - orthologs
Gene location (Human) Chr. Chromosome 3 (human)[1] Band 3q25.1-q25.2 Start 152,243,828 bp[1] End 152,465,780 bp[1]
Gene location (Mouse) Chr. Chromosome 3 (mouse)[2] Band 3|3 D Start 60,472,830 bp[2] End 60,629,750 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in Achilles tendon superficial temporal artery saphenous vein trabecular bone tail of epididymis lower lobe of lung Skeletal muscle tissue of rectus abdominis Skeletal muscle tissue of biceps brachii urethra skin of hip Top expressed in tunica media of zone of aorta tibiofemoral joint skin of external ear triceps brachii muscle stroma of bone marrow ankle intercostal muscle body of femur temporal muscle sternocleidomastoid muscle More reference expression data BioGPS More reference expression data
Gene ontology Molecular function regulatory region RNA binding double-stranded RNA binding protein binding metal ion binding RNA binding Cellular component cytoplasm centrosome cytoplasmic stress granule nucleus nucleoplasm cytosol Biological process mRNA processing regulation of RNA splicing myoblast differentiation in utero embryonic development embryonic limb morphogenesis RNA splicing nervous system development regulation of alternative mRNA splicing, via spliceosome Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 4154 56758 Ensembl ENSG00000152601 ENSMUSG00000027763 UniProt Q9NR56 Q86VM6 Q9JKP5 RefSeq (mRNA) NM_001314057 NM_021038 NM_207292 NM_207293 NM_207294 NM_207295 NM_207296 NM_207297 NM_001363870 NM_001253708 NM_001253709 NM_001253710 NM_001253711 NM_001253713 NM_020007 NM_001310514 RefSeq (protein) NP_001300986 NP_066368 NP_997175 NP_997176 NP_997177 NP_997178 NP_997179 NP_997180 NP_001350799 NP_001363747 NP_001363748 NP_001363749 NP_001363750 NP_001363751 NP_001363752 NP_001363753 NP_001363754 NP_001363755 NP_001363756 NP_001363757 NP_001363758 NP_001363759 NP_001363760 NP_001363761 NP_001363762 NP_001363763 NP_001363764 NP_001363765 NP_001363766 NP_001363767 NP_001363768 NP_001363769 NP_001363770 NP_001363771 NP_001363772 NP_001363773 NP_001363774 NP_001363775 NP_001363776 NP_001363777 NP_001363778 NP_001363780 NP_001363782 NP_001300986.1 NP_997178.1 NP_997179.1 NP_997180.1 NP_001240637 NP_001240638 NP_001240639 NP_001240640 NP_001240642 NP_001297443 NP_064391 Location (UCSC) Chr 3: 152.24 – 152.47 Mb Chr 3: 60.47 – 60.63 Mb PubMed search [3] [4]
Wikidata
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Human MBNL1 is an alternative splicing regulator that harbors dual function as both a repressor and activator for terminal muscle differentiation.^[10] The repressive function of Human MBNL1 by sequestering at normal splice sites has been shown to lead to RNA-splicing defects that lead to muscular diseases.^[11] The gene can be alternatively spliced into multiple functionally distinct isoforms, some of which linked to be involved in cancer biology.^[12]

Human MBNL1 is a 370 amino acid protein^[13] composed of four Zinc Finger protein domains of the CCCH type linked in tandem.^[10] The MBNL1 protein specifically binds to double stranded CUG RNA expansions.^[14] The Zinc Finger domains play a role in both protein:protein contacts as well as RNA:protein contacts when bound to an oligonucleotide.^[10]