The drastic reduction of SMN protein in SMA I spinal cord motor neurons is not due to inefficient transcription.
Spinal muscular atrophy (SMA) is caused by homozygous absence of the telomeric copy of the survival motor neuron (SMNt) gene. SMNt and its homologous centromeric copy (SMNc) encode the SMN protein, which is markedly reduced in SMA I patients. We have performed SMN transcript and protein studies on spinal cord sections of an SMA I patient using in situ hybridization and immunofluorescence. While the amount of protein was negligible, the level of transcripts was comparable with that of controls. These findings suggest that the reduced protein level is not caused by a deficient transcription of the SMNc gene.
Mirabella
M
M
Department of Neurology, Catholic University, Largo F. Vito, 1, I-00168 Rome, Italy.
Servidei
S
S
Broccolini
A
A
Gandolfi
N
N
Ricci
E
E
Neri
G
G
Tonali
P
P
Brahe
C
C
D001324:Autoantigens / Q000235:genetics*; D002470:Cell Survival; D002503:Centromere / Q000235:genetics; D005786:Gene Expression Regulation; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000378:metabolism* / Q000473:pathology; D009134:Muscular Atrophy, Spinal / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D017411:Ribonucleoproteins, Small Nuclear / Q000235:genetics; D013116:Spinal Cord / Q000378:metabolism* / Q000473:pathology; D014158:Transcription, Genetic; D055517:snRNP Core Proteins
D001324:Autoantigens; D017411:Ribonucleoproteins, Small Nuclear; C526417:SNRPN protein, human; D055517:snRNP Core Proteins