scholarly journals A novel cell immunoassay to measure survival of motor neurons protein in blood cells

BMC Neurology ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Stephen J Kolb ◽  
Amelie K Gubitz ◽  
Robert F Olszewski ◽  
Elizabeth Ottinger ◽  
Charlotte J Sumner ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Blood Cells ◽  
Survival Of Motor Neurons

scholarly journals The Survival of Motor Neurons Protein Determines the Capacity for snRNP Assembly: Biochemical Deficiency in Spinal Muscular Atrophy

2005 ◽  
Vol 25 (13) ◽  
pp. 5543-5551 ◽  
Author(s):  
Lili Wan ◽  
Daniel J. Battle ◽  
Jeongsik Yong ◽  
Amelie K. Gubitz ◽  
Stephen J. Kolb ◽  
...  
Keyword(s):  
Spinal Muscular Atrophy ◽  
Motor Neurons ◽  
Muscular Atrophy ◽  
Protein Levels ◽  
Small Nuclear Ribonucleoprotein ◽  
Cell Extracts ◽  
Smn Complex ◽  
Survival Of Motor Neurons ◽  
Smn Protein ◽  
Nuclear Ribonucleoprotein

ABSTRACT Reduction of the survival of motor neurons (SMN) protein levels causes the motor neuron degenerative disease spinal muscular atrophy, the severity of which correlates with the extent of reduction in SMN. SMN, together with Gemins 2 to 7, forms a complex that functions in the assembly of small nuclear ribonucleoprotein particles (snRNPs). Complete depletion of the SMN complex from cell extracts abolishes snRNP assembly, the formation of heptameric Sm cores on snRNAs. However, what effect, if any, reduction of SMN protein levels, as occurs in spinal muscular atrophy patients, has on the capacity of cells to produce snRNPs is not known. To address this, we developed a sensitive and quantitative assay for snRNP assembly, the formation of high-salt- and heparin-resistant stable Sm cores, that is strictly dependent on the SMN complex. We show that the extent of Sm core assembly is directly proportional to the amount of SMN protein in cell extracts. Consistent with this, pulse-labeling experiments demonstrate a significant reduction in the rate of snRNP biogenesis in low-SMN cells. Furthermore, extracts of cells from spinal muscular atrophy patients have a lower capacity for snRNP assembly that corresponds directly to the reduced amount of SMN. Thus, SMN determines the capacity for snRNP biogenesis, and our findings provide evidence for a measurable deficiency in a biochemical activity in cells from patients with spinal muscular atrophy.

SMN complexes of nucleus and cytoplasm: A proteomic study for SMA therapy

2010 ◽  
Vol 1 (4) ◽  
Author(s):  
Heidi Fuller ◽  
Glenn Morris
Keyword(s):  
Motor Neurons ◽  
Muscular Atrophy ◽  
Ubiquitin Proteasome System ◽  
Neuromuscular Disorder ◽  
Nuclear Extracts ◽  
Smn Complex ◽  
Proteomic Study ◽  
Ubiquitin Proteasome ◽  
Survival Of Motor Neurons ◽  
Smn Protein

AbstractReduced levels of the survival of motor neurons protein (SMN), cause the inherited neuromuscular disorder, spinal muscular atrophy (SMA). The majority of therapeutic approaches to date have been focused on finding ways to increase expression of functional SMN protein, though stabilization of SMN protein may also be an important consideration. SMN interacts, directly or indirectly, stably or transiently, with a large number of other proteins, some of which contribute to SMN stability and may therefore be potential targets for SMA therapy. We recently characterized the nuclear SMN interactome using LC-MALDI-TOF/TOF analysis of anti-SMN pull-downs and identified myb-binding protein-1a (Mybbp1a) as a novel partner. In light of interest in cytoplasm-specific roles of the SMN complex, we have applied the same approach to characterise the cytoplasmic SMN interactome. We now show that SMN complexes from HeLa cytoplasmic extracts differ significantly from those found in nuclear extracts, with gemin5, importinbeta and annexin A2 easily detected only in the cytoplasmic extracts, whereas interaction of SMN with Mybbp1a appears to occur only in the nucleus. SMN is ubiquitinylated and we also found proteins of the ubiquitin-proteasome system associated with SMN in the cytoplasm.

scholarly journals The Drosophila melanogaster Cajal body

2006 ◽  
Vol 172 (6) ◽  
pp. 875-884 ◽  
Author(s):  
Ji-Long Liu ◽  
Christine Murphy ◽  
Michael Buszczak ◽  
Sarah Clatterbuck ◽  
Robyn Goodman ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Motor Neurons ◽  
Nuclear Body ◽  
Nuclear Bodies ◽  
Cajal Body ◽  
Small Nuclear Rna ◽  
Nuclear Rna ◽  
Survival Of Motor Neurons ◽  
And Function ◽  
Histone Locus

Cajal bodies (CBs) are nuclear organelles that are usually identified by the marker protein p80-coilin. Because no orthologue of coilin is known in Drosophila melanogaster, we identified D. melanogaster CBs using probes for other components that are relatively diagnostic for CBs in vertebrate cells. U85 small CB–specific RNA, U2 small nuclear RNA, the survival of motor neurons protein, and fibrillarin occur together in a nuclear body that is closely associated with the nucleolus. Based on its similarity to CBs in other organisms, we refer to this structure as the D. melanogaster CB. Surprisingly, the D. melanogaster U7 small nuclear RNP resides in a separate nuclear body, which we call the histone locus body (HLB). The HLB is invariably colocalized with the histone gene locus. Thus, canonical CB components are distributed into at least two nuclear bodies in D. melanogaster. The identification of these nuclear bodies now permits a broad range of questions to be asked about CB structure and function in a genetically tractable organism.

scholarly journals Lymphotropic Herpesvirus saimiri Uses the SMN Complex To Assemble Sm Cores on Its Small RNAs

2005 ◽  
Vol 25 (2) ◽  
pp. 602-611 ◽  
Author(s):  
Tracey J. Golembe ◽  
Jeongsik Yong ◽  
Daniel J. Battle ◽  
Wenqin Feng ◽  
Lili Wan ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Small Rnas ◽  
Herpesvirus Saimiri ◽  
New World Monkeys ◽  
Infectious Agents ◽  
Sm Proteins ◽  
General Utility ◽  
Smn Complex ◽  
Survival Of Motor Neurons ◽  
Very High

ABSTRACT The lymphotropic Herpesvirus saimiri (HVS) causes acute leukemia, T-cell lymphoma, and death in New World monkeys. HVS encodes seven small RNAs (HSURs) of unknown function. The HSURs acquire host Sm proteins and assemble Sm cores similar to those found on the spliceosomal small nuclear RNPs (snRNPs). Here we show that, like host snRNPs, HSURs use the SMN (survival of motor neurons) complex to assemble Sm cores. The HSURs bind the SMN complex directly and with very high affinity, similar to or higher than that of host snRNAs, and can outcompete host snRNAs for SMN-dependent assembly into RNPs. These observations highlight the general utility of the SMN complex for RNP assembly and suggest that infectious agents that engage the SMN complex may burden SMN-dependent pathways, possibly leading to a deleterious reduction in available SMN complex for essential host functions.

scholarly journals SMN-independent Subunits of the SMN Complex

2007 ◽  
Vol 282 (38) ◽  
pp. 27953-27959 ◽  
Author(s):  
Daniel J. Battle ◽  
Mumtaz Kasim ◽  
Jin Wang ◽  
Gideon Dreyfuss
Keyword(s):  
Motor Neurons ◽  
Atp Hydrolysis ◽  
Muscular Atrophy ◽  
Small Nuclear Rna ◽  
Small Nuclear Ribonucleoprotein ◽  
Cell Extracts ◽  
Smn Complex ◽  
Small Nuclear Rnas ◽  
Survival Of Motor Neurons ◽  
Nuclear Ribonucleoprotein

The survival of motor neurons (SMN) complex is essential for the biogenesis of small nuclear ribonucleoprotein (snRNP) complexes in eukaryotic cells. Reduced levels of SMN cause the motor neuron degenerative disease, spinal muscular atrophy. We identify here stable subunits of the SMN complex that do not contain SMN. Sedimentation and immunoprecipitation experiments using cell extracts reveal at least three complexes composed of Gemin3, -4, and -5; Gemin6, -7, and unrip; and SMN with Gemin2, as well as free Gemin5. Complexes containing Gemin3-Gemin4-Gemin5 and Gemin6-Gemin7-unrip persist at similar levels when SMN is reduced. In cells, immunofluorescence microscopy shows differential localization of Gemin5 after cell stress. We further show that the Gemin5-containing subunits bind small nuclear RNA independently of the SMN complex and without a requirement for exogenous ATP. ATP hydrolysis is, however, required for displacement of small nuclear RNAs from the Gemin5-containing subunits and their assembly into snRNPs. These findings demonstrate a modular nature of the SMN complex and identify a new intermediate in the snRNP assembly process.

scholarly journals The Epstein–Barr virus nuclear antigen-6 protein co-localizes with EBNA-3 and survival of motor neurons protein

Virology ◽  
2004 ◽  
Vol 318 (1) ◽  
pp. 280-294 ◽  
Author(s):  
Kenia G. Krauer ◽  
Marion Buck ◽  
Deanna K. Belzer ◽  
James Flanagan ◽  
Grace M. Chojnowski ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Epstein Barr Virus ◽  
Nuclear Antigen ◽  
Barr Virus ◽  
Survival Of Motor Neurons ◽  
Epstein Barr

scholarly journals A subset of SMN complex members have a specific role in tissue regeneration via ERBB pathway-mediated proliferation

2019 ◽  
Author(s):  
Wuhong Pei ◽  
Lisha Xu ◽  
Zelin Chen ◽  
Claire C Slevin ◽  
Kade P Pettie ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Tissue Regeneration ◽  
Hair Cells ◽  
Muscular Atrophy ◽  
Essential Gene ◽  
Genetic Diseases ◽  
Rna Seq ◽  
Genetic Pathways ◽  
Smn Complex ◽  
Survival Of Motor Neurons

AbstractSpinal Muscular Atrophy (SMA) is the most common genetic disease in childhood. SMA is generally caused by mutations in SMN1. The Survival of Motor Neurons (SMN) complex consists of SMN1, Gemins (2–8) and Strap/Unrip. We previously demonstrated smn1 and gemin5 inhibited tissue regeneration in zebrafish. Here we investigated each individual SMN complex member and identified gemin3 as another regeneration-essential gene. These three genes are likely pan-regenerative since they affect the regeneration of hair cells, liver and caudal fin. RNA-Seq and miRNA-Seq analyses reveal that smn1, gemin3, and gemin5 are linked to a common set of genetic pathways, including the tp53 and ErbB pathways. Additional studies indicated all three genes facilitate regeneration by inhibiting the ErbB pathway, thereby allowing cell proliferation in the injured neuromasts. This study provides a new understanding of the SMN complex and a potential etiology for SMA and potentially other rare unidentified genetic diseases with similar symptoms.

scholarly journals The SMN Complex Is Associated with snRNPs throughout Their Cytoplasmic Assembly Pathway

2002 ◽  
Vol 22 (18) ◽  
pp. 6533-6541 ◽  
Author(s):  
Séverine Massenet ◽  
Livio Pellizzoni ◽  
Sergey Paushkin ◽  
Iain W. Mattaj ◽  
Gideon Dreyfuss
Keyword(s):  
Motor Neurons ◽  
Muscular Atrophy ◽  
Sm Proteins ◽  
Assembly Pathway ◽  
Smn Complex ◽  
Complex Functions ◽  
Survival Of Motor Neurons ◽  
The Common ◽  
Smn Protein ◽  
Cytoplasmic Assembly

ABSTRACT The common neurodegenerative disease spinal muscular atrophy is caused by reduced levels of the survival of motor neurons (SMN) protein. SMN associates with several proteins (Gemin2 to Gemin6) to form a large complex which is found both in the cytoplasm and in the nucleus. The SMN complex functions in the assembly and metabolism of several RNPs, including spliceosomal snRNPs. The snRNP core assembly takes place in the cytoplasm from Sm proteins and newly exported snRNAs. Here, we identify three distinct cytoplasmic SMN complexes, each representing a defined intermediate in the snRNP biogenesis pathway. We show that the SMN complex associates with newly exported snRNAs containing the nonphosphorylated form of the snRNA export factor PHAX. The second SMN complex identified contains assembled Sm cores and m3G-capped snRNAs. Finally, the SMN complex is associated with a preimport complex containing m3G-capped snRNP cores bound to the snRNP nuclear import mediator snurportin1. Thus, the SMN complex is associated with snRNPs during the entire process of their biogenesis in the cytoplasm and may have multiple functions throughout this process.

Sign in / Sign up

Export Citation Format

Share Document