Profilin I colocalizes with speckles and Cajal bodies: a possible role in pre-mRNA splicing.
Profilin is one of the major components controlling actin polymerization. Here, profilin I was located in fibroblasts and HeLa cells by the use of two different sets of affinity-purified antibodies. Both antibody preparations labeled nuclei in a speckle-like pattern and displayed extensive colocalization with small nuclear ribonucleoprotein particle (snRNP)-core proteins and p80 coilin-containing Cajal bodies. Treatment with actinomycin D led to largely similar reorganizations of snRNPs and profilin, while profilin and Cajal bodies separated under these conditions. One of the profilin antibodies interfered with pre-mRNA splicing in vitro, further indicating a role for profilin during pre-mRNA processing.
Department of Cell Biology, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden.
Petra
P
Skare
Jan-Peter
JP
Kreivi
Asa
A
Bergström
Roger
R
Karlsson
D000818:Animals; D000906:Antibodies / Q000276:immunology / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D020541:Coiled Bodies / Q000378:metabolism*; D003285:Contractile Proteins; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D007150:Immunohistochemistry; D008840:Microfilament Proteins / Q000378:metabolism*; D051304:Profilins; D020033:Protein Isoforms / Q000378:metabolism; D012326:RNA Splicing / Q000502:physiology*; D017411:Ribonucleoproteins, Small Nuclear / Q000378:metabolism*
D000906:Antibodies; D003285:Contractile Proteins; D008840:Microfilament Proteins; C495738:PFN1 protein, human; D051304:Profilins; D020033:Protein Isoforms; D017411:Ribonucleoproteins, Small Nuclear