Mitochondrial protein p32 can accumulate in the nucleus.
Human p32 was first isolated associated with the splicing factor ASF/SF-2. The p32 protein is translated as pre-protein from which a mitochondrial import signal is cleaved off to create the mature p32. The majority of p32 is consequently found in the mitochondria. In this study we investigated extramitochondrial p32. An increased nuclear localisation of endogenous p32 was demonstrated as a response to leptomycin B or actinomycin D treatment of cells. Mature p32 gene and deletion mutants were cloned into enhanced green fluorescence protein reporter plasmids. On transfection, EGFP-p32 protein was mainly localised to the cytoplasm and to a lesser extent to the nucleus of transfected COS cells. Upon treatment with actinomycin D or leptomycin B, the EGFP-p32 protein accumulated in the nucleus. Deletion analysis indicated which regions of EGFP-p32 are involved in nuclear export and nuclear import.
Broegelmann Research Laboratory, University of Bergen, Bergen, N-5021, Norway.
K A
KA
Brokstad
K H
KH
Kalland
W C
WC
Russell
D A
DA
Matthews
D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000818:Animals; D019556:COS Cells; D002352:Carrier Proteins; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism*; D003609:Dactinomycin / Q000494:pharmacology; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology; D015694:Gene Products, rev / Q000378:metabolism; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006801:Humans; D018960:Hyaluronan Receptors; D007202:Indicators and Reagents / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008562:Membrane Glycoproteins; D000432:Methanol / Q000737:chemistry; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins; D011951:Receptors, Complement / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012261:Ribonucleoproteins / Q000378:metabolism; D017384:Sequence Deletion; D016707:Tissue Fixation; D014162:Transfection
C087299:C1QBP protein, human; D002352:Carrier Proteins; D005231:Fatty Acids, Unsaturated; D015694:Gene Products, rev; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D018960:Hyaluronan Receptors; D007202:Indicators and Reagents; D008164:Luminescent Proteins; D008562:Membrane Glycoproteins; D024101:Mitochondrial Proteins; D011951:Receptors, Complement; D011993:Recombinant Fusion Proteins; D012261:Ribonucleoproteins; C032402:complement 1q receptor; D049452:Green Fluorescent Proteins; D003609:Dactinomycin; C038753:leptomycin B; D000432:Methanol