The survival motor neuron (SMN) gene is the putative disease gene for human spinal muscular atrophy (SMA), an autosomal recessive disorder characterized by progressive degeneration of lower motor neurons. Two copies of the gene, centromeric and telomeric, are present in the same 5q13 chromosomal region in humans. However, only the telomeric gene is affected in SMA. The SMN gene(s) encode(s) a n...

Reduction in the expression of the survival of motor neurons (SMN) protein results in spinal muscular atrophy (SMA), a common motor neuron degenerative disease. SMN is part of a large macromolecular complex (the SMN complex) that includes at least six additional proteins called Gemins (Gemin2-7). The SMN complex is expressed in all cells and is present throughout the cytoplasm and in the nucleu...

Spinal muscular atrophy (SMA), a progressive neurodegenerative disease affecting motor neurons, is caused by mutations or deletions of the SMN1 gene encoding the survival of motor neuron (SMN) protein. In immortalized non-neuronal cell lines, SMN has been shown to form a ribonucleoprotein (RNP) complex with Gemin proteins, which is essential for the assembly of small nuclear RNPs (snRNPs). An a...

Spinal Muscular Atrophy (SMA) is an inherited neurodegenerative condition caused by reduction in functional Survival Motor Neurones Protein (SMN). SMN has been implicated in transport of mRNA in neural cells for local translation. We previously identified microtubule-dependant mobile vesicles rich in SMN and SmB, a member of the Sm family of snRNP-associated proteins, in neural cells. By compar...

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 a...

The Survival Motor Neuron (SMN) gene shows deletions in the majority of patients with Spinal Muscular Atrophy (SMA), a disease of motor neuron degeneration. To date only two missense mutations have been reported in SMN in patients with SMA. The fact that no SMN-homologues have been forthcoming from data-base searching has resulted in a lack of hypotheses concerning the structural and functional...

In eukaryotic cells, the biogenesis of spliceosomal small nuclear ribonucleoproteins (snRNPs) and likely other RNPs is mediated by an assemblyosome, the survival of motor neurons (SMN) complex. The SMN complex, composed of SMN and the Gemins (2-7), binds to the Sm proteins and to snRNAs and constructs the heptameric rings, the common cores of Sm proteins, on the Sm site (AU(56)G) of the snRNAs....

Spinal Muscular Atrophy (SMA), a recessive hereditary neurodegenerative disease in humans, has been linked to mutations in the survival motor neuron (SMN) gene. SMA patients display early onset lethality coupled with motor neuron loss and skeletal muscle atrophy. We used Drosophila, which encodes a single SMN ortholog, survival motor neuron (Smn), to model SMA, since reduction of Smn function l...

Spinal muscular atrophy (SMA) is a neurodegenerative disease characterized by loss of spinal motor neurons. The gene encoding the survival of motor neurons (SMN) protein is mutated in >95% of SMA cases. SMN is the central component of a large oligomeric complex, including Gemins2-7, that is necessary and sufficient for the in vivo assembly of Sm proteins onto the small nuclear (sn)RNAs that med...

The actin-binding protein plastin 3 (PLS3) has been identified as a modifier of the human motoneuron disease spinal muscular atrophy (SMA). SMA is caused by decreased levels of the survival motor neuron protein (SMN) and in its most severe form causes death in infants and young children. To understand the mechanism of PLS3 in SMA, we have analyzed pls3 RNA and protein in zebrafish smn mutants. ...