SNRP

U-snRNPs which are a pivotal part of spliceosomes, are created between small non-coding nuclear RNAs and a protein moiety. Whereas the 7 Sm proteins are conserved, the RNP antigens are exclusive for each U-snRNP subclass.

Nucleosome core proteins are a group of proteins which are necessary for DNA packaging in eukaryotes. Every core contains an octamer with 2 copies of each histone 2A, 2B, 3 and 4 around which an approx. 140 bp section of DNA is wound twice.

Small nuclear ribonucleoprotein polypeptide G (SNRPG) is a member of the snRNP Sm proteins family. There are at least 7 isoforms, B/B, E, F, G, D1, D2, and D3. This class of common proteins has a vital role in the biogenesis of the snRNPs. The human Sm G genes are mapped to chromosomes 2. Furthermore, these proteins represent the major targets for the supposed anti-Sm auto-antibodies which are diagnostic for SLE (systemic lupus erythematosus). One class of these autoantibodies reacts specifically with native Sm E-F-G complexes.

SNRPF is a member of the snRNP Sm proteins family. There are at least seven isoforms, E, F, G, D1, D2, D3 and B/B. This type of common proteins have a crucial part in the biogenesis of the snRNPs. Moreover, they represent the major targets for the so-called anti-Sm auto-antibodies that are diagnostic for systemic lupus erythematosus (SLE). SNRPF assist in the cytoplasmic construction of the UsnRNPs by binding to aconserved Sm site on UsnRNA and forming a stable snRNP core complex.

SNRPE facilitates the cytoplasmic construction of the UsnRNPs by binding to a conserved Sm site on UsnRNA and forming a stable snRNP core complex. While a core protein to UsnRNP, the SNRPE connects with the entire U family of snRNAs including U1–U6. In addition, SNRPE interacts with DDX20 and Small nuclear ribonucleoprotein polypeptide F.

SNRPD3 is a small nuclear ribonucleoprotein (snRNPs) that contains the spliceosome in eukaryotes. SNRPD3 is essential for pre-mRNA splicing and small nuclear ribonucleoprotein biogenesis. Alternative splicing happens in this locus and two transcript variants encoding the same protein were branded.

SNRPD3 is a small nuclear ribonucleoprotein (snRNPs) that contains the spliceosome in eukaryotes. SNRPD3 is essential for pre-mRNA splicing and small nuclear ribonucleoprotein biogenesis. Alternative splicing happens in this locus and two transcript variants encoding the same protein were branded.

SNRPD2 is a member of the small nuclear ribonucleoprotein core protein family. SNRPD2 is a small nuclear ribonucleoprotein (snRNPs) which comprises the spliceosome in eukaryotes. SNRPD2 is required for pre-mRNA splicing and small nuclear ribonucleoprotein biogenesis.

SNRPD2 is a member of the small nuclear ribonucleoprotein core protein family. SNRPD2 is a small nuclear ribonucleoprotein (snRNPs) which comprises the spliceosome in eukaryotes. SNRPD2 is required for pre-mRNA splicing and small nuclear ribonucleoprotein biogenesis.

SNRPD1 Human Recombinant produced in SF9 is a glycosylated, polypeptide chain having a calculated molecular mass of 16kDa.
SNRPD1 is expressed with a -6x His tag at N-terminus and purified by proprietary chromatographic techniques.

SNRPC is a member of the U1 small nuclear ribonucleoprotein C family. The SNRPC protein component of the U1 small nuclear ribonucleoprotein (snRNP) particle required for the formation of the spliceosome. SNRPC participates in the processing of nuclear precursor messenger RNA splicing. snRNP particles are tackled by autoantibodies frequently produced by patients with connective tissue diseases.

SNRPC is a member of the U1 small nuclear ribonucleoprotein C family. The SNRPC protein component of the U1 small nuclear ribonucleoprotein (snRNP) particle required for the formation of the spliceosome. SNRPC participates in the processing of nuclear precursor messenger RNA splicing. snRNP particles are tackled by autoantibodies frequently produced by patients with connective tissue diseases.

SNRPB2 is a member of the RRM U1 A/B family. SNRPB2 links with stem loop IV of U2 small nuclear ribonucleoprotein (U2 snRNP) in the presence of snRNP-A. SNRPB2 has a part in pre-mRNA splicing. Autoantibodies from patients with systemic lupus erythematosus often identify epitopes on the encoded protein. A pair of transcript variants encoding the same protein were identified for this gene.

SNRPB is one of several nuclear proteins which are found in common among U1, U2, U4/U6, and U5 small ribonucleoprotein particles (snRNPs). These snRNPs are involved in pre-mRNA splicing, and the SNRPB protein may also have a role in pre-mRNA splicing or snRNP structure. SNRPB binds to the downstream cleavage product (DCP) of histone pre-mRNA in a U7 snRNP dependent manner. SNRPB functions in the U7 snRNP complex which is involved in histone 3'-end processing.

U2 small nuclear ribonucleoprotein A (SNRPA1), a 255 amino acid protein, is a component of the U2 snRNP which forms a complex with U2 snRNP B (U2B). U2 snRNP A and U2 snRNP B form together a complex which binds to the U2 snRNA hairpin IV. The configuration of the U2 snRNP A/U2 snRNP B dimer and the delicate variations of a few key residues regulate the snRNP-RNA-binding specificity.

SNRPA associates with stem loop II of the U1 small nuclear ribonucleoprotein, which binds the 5' splice site of precursor mRNAs and is essential for splicing. The SNRPA protein autoregulates itself by polyadenylation inhibition of its own pre-mRNA via dimerization and is involved in the coupling of splicing and polyadenylation. SNRPA binds stem loop II of U1 snRNA. SNRPA is the first snRNP to interact with pre-mRNA. This interaction is vital for the subsequent binding of U2 snRNP and the U4/U6/U5 tri-snRNP.

Small nuclear ribonucleoprotein complexes (abbreviated as U-snRNP) are essential for splicing of precursor mRNA molecules. U1-snRNP is the most abundant RNP particle in the nucleus and consists of one small uridylate-rich RNA (U1 RNA) complexed with several proteins: the three 68/70 kDa, A, C polypeptides are unique to the U1-snRNP particle, whereas 7 so-called Sm proteins (B/B', D1, D2, D3, E, F, G) form a core subparticle that is common to all U-snRNP complexes.
Both the U1-specific proteins and the Sm core particle are targets of autoantibodies which classically have been called the RNP and RNP-Sm specificities, respectively. A clean diagnostic distinction of these specificities has been complicated by the biochemical difficulties of producing clean subparticle fractions from native sources. The use of single recombinant proteins as antigenic targets guarantees a much higher sensitivity and specificity and is the only way to determine RNP antibodies sensu stricto without the disturbing influence of Sm antigens; also with single U1 proteins antibodies will be detected which can be missed because of steric hindrance when using the RNP-Sm complex in an assay.
Autoantibodies to U1-snRNP are present in 95% of patients with Mixed Connective Tissue Disease (MCTD) and 30% of patients with SLE. Antibodies against the 68/70 kDa protein are known to have a high clinical significance in MCTD patients. The 68/70 kDa nomenclature of this protein refers to the fact that different splice variants of the protein are found in human cells.

SNRNP25 is a member of the small nuclear ribonucleoprotein core protein family. SNRNP25 is a component of the U12-type spliceosome which is found in some eukaryotes and removes U12-type introns that are rare and have distinct splice consensus signals. The U12-type spliceosome is comprised of several small nuclear RNAs and associated proteins.