Structure, expression and chromosomal localization of human p80-coilin gene

Abstract

Coiled bodies (CBs) are non-capsular nuclear bodies with a diameter of 0.3-1 micron and appear to be composed of coiled fibrils. Human autoantibodies to CBs recognize an 80-kD nuclear protein highly enriched in CBs, and this protein has been named p80-coilin. CBs are known to assemble and disassemble during the cell cycle, with the highest number of CBs occurring at mid to late G1 where p80-coilin is assembled into several small nuclear body-like structures. In S and G2 phases, CBs become larger and their number decreases and often they are undetectable during mitosis. Using a human autoantibody as a probe for expression cloning, we initially isolated a partial cDNA encoding p80-coilin. In this report, the 5' end of the complete cDNA for p80-coilin was obtained using the 5'-RACE (rapid amplification of cDNA ends) methodology. The size of the reconstructed full-length cDNA corresponds to the 2.7-kb mRNA detected in Northern blot analysis. The complete p80-coilin protein consists of 576 amino acids with a predicted molecular mass of 62,608. A putative p80-coilin pseudogene was also detected during the rescreening of p80-coilin cDNA. To confirm the validity of the cDNA sequence, three overlapping genomic DNA clones representing the human p80-coilin gene were selected for further analysis. The complete gene for p80-coilin contains 7 exons spanning approximately 25kb. Sequence analysis of exons 1 and 2 in genomic DNA clones confirmed the accuracy of the 5' cDNA sequence derived from the 5'-RACE procedure. Furthermore, the human p80-coilin gene was localized to chromosome 17q22-23 by fluorescence in situ hybridization.

The Movement of Coiled Bodies Visualized in Living Plant Cells by the Green Fluorescent Protein

“…This fusion mechanism explains the observed decrease in coiled body number and the increase in size through the cell cycle that has been reported for several organisms (Andrade et al, 1993;Chan et al, 1994;Boudonck et al, 1998). It is noteworthy that all coiled body fusions that we observed took place at the nucleolar periphery.…”

“…When transcription is inhibited, splicing snRNPs no longer concentrate in coiled bodies but, instead, aggregate in large clusters thought to be storage sites of splicing factors (Carmo-Fonseca et al, 1992). Changes have also been observed in the size and number of coiled bodies during the cell cycle (Andrade et al, 1993;Carmo-Fonseca et al, 1993;Chan et al, 1994;Ferreira et al, 1994;Beven et al, 1995), with smaller and more coiled bodies during G 1 phase, and larger and fewer coiled bodies in S and G 2 phases of the cell cycle. Upon entry into mitosis, most coiled bodies disappear, reappearing in G 1 phase after reformation of nucleoli (Andrade et al, 1993;Ferreira et al, 1994).…”

SMN - A chaperone for nuclear RNP social occasions?

“…3 However, it was not until the 1990s that a molecular characterization of Cajal bodies began. [4][5][6][7] Since that time, the number of known cellular components that are enriched in the Cajal body has been growing. 3,[8][9][10] These components include factors important for the maturation and function of Sm-class small nuclear ribonucleoproteins (snRNPs), core particles of the spliceosome.…”

Coilin Can Form a Complex with the U7 Small Nuclear Ribonucleoprotein

“…As shown in Figure 8B, 6-histidine coilin bound to RNA homopolymers with the same specificity as endogenous coilin. Thus, coilin by itself is an RNA-binding protein in vitro.We also tested the binding properties of human coilin, which shares conserved regions at the amino and carboxy termini with Xenopus coilin but differs considerably in the middle of the molecule (Tuma et al, 1993;Chan et al, 1994;Wu et al, 1994). Using T3 RNA polymerase, we synthesized capped, sense- .…”