Datasheet

生物学的記述

Specificity	SMN Antibody (Rabbit mAb) [C8K16] detects endogenous levels of total SMN protein.
Background	Survival motor neuron protein (SMN, also called Gemin 1 in the context of the SMN–Gemin complex) is a ubiquitously expressed RNA-binding protein encoded by the SMN1 and SMN2 genes that forms the structural backbone of a multi-subunit chaperone complex dedicated to the assembly of small nuclear ribonucleoproteins (snRNPs), the core building blocks of the spliceosome. The protein contains a GEMIN2-binding region, a Tudor domain that recognizes symmetrically dimethylated arginine residues on Sm proteins, and a C‑terminal YG box that mediates SMN oligomerization; these domains position SMN at the center of a ring-like SMN complex that includes Gemin2–7 and associated factors and organizes Sm proteins around snRNAs during snRNP biogenesis. In the chaperone-assisted assembly pathway, SMN and Gemin2 accept the preloaded 5Sm complex from the CLNS1A–pICln chaperone, form an intermediate that holds SmD1/D2, SmE/F/G in a position competent for snRNA binding, and then, upon snRNA engagement, are evicted as SmD3 and SmB join to complete the heptameric ring, generating mature core snRNPs that are subsequently modified, imported into the nucleus and incorporated into spliceosomes. SMN localizes both to the cytoplasm and to nuclear gems adjacent to Cajal bodies that are enriched in snRNPs, reflecting its continuous role in snRNP maturation and trafficking in support of pre‑mRNA splicing, including correct splicing of U12-type introns that contribute to normal development of motor and proprioceptive neurons. Beyond snRNP assembly, SMN interacts with a wide range of RNA-binding and RNP proteins (such as hnRNP U/R, GAR1, snoRNP components) and participates in R-loop resolution at transcription termination regions by assisting removal of RNA–DNA hybrids generated by RNA polymerase II, highlighting broader functions in RNA metabolism, transcription termination and possibly telomerase and cytoskeletal regulation. The direct disease relevance of SMN is established by spinal muscular atrophy (SMA), an autosomal recessive motoneuron disease caused by loss-of-function mutations or deletions in SMN1 that reduce full-length SMN protein and lead to widespread splicing defects, with spinal motor neurons particularly vulnerable to reduced snRNP availability and consequent disturbances in neuromuscular junction formation and spinal circuit development. SMN2, a nearly identical centromeric copy of SMN1, modifies disease severity in a dose-dependent manner but predominantly produces transcripts lacking exon 7 due to a single nucleotide change in exon 7 that disrupts splicing; only a minority of SMN2 transcripts are full-length and generate functional SMN, so SMN2 cannot fully compensate for SMN1 loss, although higher SMN2 copy number is associated with milder SMA phenotypes. Developmental regulation of SMN expression shows high levels from SMN1 and SMN2 in early stages followed by progressive decline, suggesting a critical window when reduced SMN drops below threshold and irreversible defects at neuromuscular junctions and spinal circuits occur; this timing underlies therapeutic strategies that upregulate SMN2 splicing to restore SMN before synaptic maturation is compromised.

Specificity

SMN Antibody (Rabbit mAb) [C8K16] detects endogenous levels of total SMN protein.

Background

Survival motor neuron protein (SMN, also called Gemin 1 in the context of the SMN–Gemin complex) is a ubiquitously expressed RNA-binding protein encoded by the SMN1 and SMN2 genes that forms the structural backbone of a multi-subunit chaperone complex dedicated to the assembly of small nuclear ribonucleoproteins (snRNPs), the core building blocks of the spliceosome. The protein contains a GEMIN2-binding region, a Tudor domain that recognizes symmetrically dimethylated arginine residues on Sm proteins, and a C‑terminal YG box that mediates SMN oligomerization; these domains position SMN at the center of a ring-like SMN complex that includes Gemin2–7 and associated factors and organizes Sm proteins around snRNAs during snRNP biogenesis. In the chaperone-assisted assembly pathway, SMN and Gemin2 accept the preloaded 5Sm complex from the CLNS1A–pICln chaperone, form an intermediate that holds SmD1/D2, SmE/F/G in a position competent for snRNA binding, and then, upon snRNA engagement, are evicted as SmD3 and SmB join to complete the heptameric ring, generating mature core snRNPs that are subsequently modified, imported into the nucleus and incorporated into spliceosomes. SMN localizes both to the cytoplasm and to nuclear gems adjacent to Cajal bodies that are enriched in snRNPs, reflecting its continuous role in snRNP maturation and trafficking in support of pre‑mRNA splicing, including correct splicing of U12-type introns that contribute to normal development of motor and proprioceptive neurons. Beyond snRNP assembly, SMN interacts with a wide range of RNA-binding and RNP proteins (such as hnRNP U/R, GAR1, snoRNP components) and participates in R-loop resolution at transcription termination regions by assisting removal of RNA–DNA hybrids generated by RNA polymerase II, highlighting broader functions in RNA metabolism, transcription termination and possibly telomerase and cytoskeletal regulation. The direct disease relevance of SMN is established by spinal muscular atrophy (SMA), an autosomal recessive motoneuron disease caused by loss-of-function mutations or deletions in SMN1 that reduce full-length SMN protein and lead to widespread splicing defects, with spinal motor neurons particularly vulnerable to reduced snRNP availability and consequent disturbances in neuromuscular junction formation and spinal circuit development. SMN2, a nearly identical centromeric copy of SMN1, modifies disease severity in a dose-dependent manner but predominantly produces transcripts lacking exon 7 due to a single nucleotide change in exon 7 that disrupts splicing; only a minority of SMN2 transcripts are full-length and generate functional SMN, so SMN2 cannot fully compensate for SMN1 loss, although higher SMN2 copy number is associated with milder SMA phenotypes. Developmental regulation of SMN expression shows high levels from SMN1 and SMN2 in early stages followed by progressive decline, suggesting a critical window when reduced SMN drops below threshold and irreversible defects at neuromuscular junctions and spinal circuits occur; this timing underlies therapeutic strategies that upregulate SMN2 splicing to restore SMN before synaptic maturation is compromised.

使用情報

Application

WB, IP, IF, FCM

Dilution

WB	IP	IF	FCM
1:1000	1:30	1:50	1:500

Reactivity

Human, Mouse

Source

Rabbit Monoclonal Antibody

MW

32 kDa

Storage Buffer

PBS, pH 7.2+50% Glycerol+0.05% BSA+0.01% NaN3

Storage
(from the date of receipt)

-20°C (avoid freeze-thaw cycles), 2 years

プロトコール

References

https://pubmed.ncbi.nlm.nih.gov/29872871/
https://pubmed.ncbi.nlm.nih.gov/28556834/

SMN Antibody (Rabbit mAb) [C8K16]

生物学的記述

使用情報

References

Application Data