PMID- 10531003
OWN - NLM
STAT- MEDLINE
DCOM- 20000309
LR  - 20081121
IS  - 0960-9822 (Print)
IS  - 0960-9822 (Linking)
VI  - 9
IP  - 19
DP  - 1999 Oct 7
TI  - Newly assembled snRNPs associate with coiled bodies before speckles, suggesting a
      nuclear snRNP maturation pathway.
PG  - 1065-74
AB  - BACKGROUND: Small nuclear ribonucleoproteins (snRNPs), which are essential
      components of the mRNA splicing machinery, comprise small nuclear RNAs, each
      complexed with a set of proteins. An early event in the maturation of snRNPs is
      the binding of the core proteins - the Sm proteins - to snRNAs in the cytoplasm
      followed by nuclear import. Immunolabelling with antibodies against Sm proteins
      shows that splicing snRNPs have a complex steady-state localisation within the
      nucleus, the result of the association of snRNPs with several distinct subnuclear
      structures. These include speckles, coiled bodies and nucleoli, in addition to a 
      diffuse nucleoplasmic compartment. The reasons for snRNP accumulation in these
      different structures are unclear. RESULTS: When mammalian cells were
      microinjected with plasmids encoding the Sm proteins B, D1 and E, each tagged
      with either the green fluorescent protein (GFP) or yellow-shifted GFP (YFP), a
      pulse of expression of the tagged proteins was observed. In each case, the newly 
      synthesised GFP/YFP-labelled snRNPs accumulated first in coiled bodies and
      nucleoli, and later in nuclear speckles. Mature snRNPs localised immediately to
      speckles upon entering the nucleus after cell division. CONCLUSIONS: The complex 
      nuclear localisation of splicing snRNPs results, at least in part, from a
      specific pathway for newly assembled snRNPs. The data demonstrate that the
      distribution of snRNPs between coiled bodies and speckles is directed and not
      random.
FAU - Sleeman, J E
AU  - Sleeman JE
AD  - Department of Biochemistry University of Dundee Wellcome Trust Building, Dow
      Street, Dundee, DD1 5EH, UK.
FAU - Lamond, A I
AU  - Lamond AI
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Curr Biol
JT  - Current biology : CB
JID - 9107782
RN  - 0 (Autoantigens)
RN  - 0 (Bacterial Proteins)
RN  - 0 (Luminescent Proteins)
RN  - 0 (Recombinant Fusion Proteins)
RN  - 0 (Ribonucleoproteins, Small Nuclear)
RN  - 0 (SME1 protein, S cerevisiae)
RN  - 0 (Saccharomyces cerevisiae Proteins)
RN  - 0 (snRNP Core Proteins)
RN  - 0 (yellow fluorescent protein, Bacteria)
RN  - 147336-22-9 (Green Fluorescent Proteins)
SB  - IM
MH  - Autoantigens/metabolism
MH  - Bacterial Proteins/metabolism
MH  - Cell Nucleolus/physiology
MH  - Cell Nucleus/*metabolism
MH  - Coiled Bodies/*metabolism
MH  - Green Fluorescent Proteins
MH  - HeLa Cells
MH  - Humans
MH  - Kinetics
MH  - Luminescent Proteins/metabolism
MH  - Microscopy, Confocal
MH  - Recombinant Fusion Proteins/metabolism
MH  - Ribonucleoproteins, Small Nuclear/*metabolism
MH  - *Saccharomyces cerevisiae Proteins
MH  - Time Factors
MH  - Tumor Cells, Cultured
MH  - snRNP Core Proteins
EDAT- 1999/10/26 09:00
MHDA- 2000/03/11 09:00
CRDT- 1999/10/26 09:00
PHST- 1999/10/26 09:00 [pubmed]
PHST- 2000/03/11 09:00 [medline]
PHST- 1999/10/26 09:00 [entrez]
AID - S0960-9822(99)80475-8 [pii]
PST - ppublish
SO  - Curr Biol. 1999 Oct 7;9(19):1065-74.