Residual Cajal bodies in coilin knockout mice fail to recruit Sm snRNPs and SMN, the spinal muscular atrophy gene product.
Cajal bodies (CBs) are nuclear suborganelles involved in the biogenesis of small nuclear ribonucleoproteins (snRNPs). In addition to snRNPs, they are highly enriched in basal transcription and cell cycle factors, the nucleolar proteins fibrillarin (Fb) and Nopp140 (Nopp), the survival motor neuron (SMN) protein complex, and the CB marker protein, p80 coilin. We report the generation of knockout mice lacking the COOH-terminal 487 amino acids of coilin. Northern and Western blot analyses demonstrate that we have successfully removed the full-length coilin protein from the knockout animals. Some homozygous mutant animals are viable, but their numbers are reduced significantly when crossed to inbred backgrounds. Analysis of tissues and cell lines from mutant animals reveals the presence of extranucleolar foci that contain Fb and Nopp but not other typical nucleolar markers. These so-called "residual" CBs neither condense Sm proteins nor recruit members of the SMN protein complex. Transient expression of wild-type mouse coilin in knockout cells results in formation of CBs and restores these missing epitopes. Our data demonstrate that full-length coilin is essential for proper formation and/or maintenance of CBs and that recruitment of snRNP and SMN complex proteins to these nuclear subdomains requires sequences within the coilin COOH terminus.
Tucker
K E
KE
Department of Genetics, and Program in Cell Biology, Case Western Reserve University and University Hospitals of Cleveland, Cleveland, OH 44106, USA.
Berciano
M T
MT
Jacobs
E Y
EY
LePage
D F
DF
Shpargel
K B
KB
Rossire
J J
JJ
Chan
E K
EK
Lafarga
M
M
Conlon
R A
RA
Matera
A G
AG
D000818:Animals; D001324:Autoantigens / Q000378:metabolism; D015152:Blotting, Northern; D002460:Cell Line; D002466:Cell Nucleolus / Q000378:metabolism / Q000648:ultrastructure; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D020541:Coiled Bodies / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D017362:Cyclic AMP Response Element-Binding Protein; D005328:Fetal Viability / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D018390:Gene Targeting; D049452:Green Fluorescent Proteins; D006720:Homozygote; D008164:Luminescent Proteins / Q000235:genetics; D051379:Mice; D018345:Mice, Knockout / Q000235:genetics*; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism; D009928:Organ Specificity; D010750:Phosphoproteins / Q000378:metabolism; D012326:RNA Splicing; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology; D017411:Ribonucleoproteins, Small Nuclear / Q000378:metabolism*; D055532:SMN Complex Proteins; D015996:Survival Rate; D055517:snRNP Core Proteins
D001324:Autoantigens; D002868:Chromosomal Proteins, Non-Histone; D017362:Cyclic AMP Response Element-Binding Protein; D008164:Luminescent Proteins; C075564:NOLC1 protein, human; D009419:Nerve Tissue Proteins; C513068:Nolc1 protein, mouse; D009687:Nuclear Proteins; D010750:Phosphoproteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D017411:Ribonucleoproteins, Small Nuclear; D055532:SMN Complex Proteins; C047458:fibrillarin; D055517:snRNP Core Proteins; C068921:p80-coilin; D049452:Green Fluorescent Proteins