Solubility partitioning of C/EBPβ on the rat hepatocyte nuclear matrix by hydrophobic interactions
2002
Autori:
Uskoković, AleksandraVidaković, Melita
Dinić, Svetlana
Ivanović-Matić, Svetlana
Martinović, Vesna
Poznanović, Goran
Tip dokumenta:
Članak u časopisu (Objavljena verzija)
Metapodaci
Prikaz svih podataka o dokumentuApstrakt:
The greatest part of nuclear C/EBP (a major 35 kD protein, 30 and 38 kD isoforms) was
observed to partition with the nuclear matrix. Cross-linking experiments with formaldehyde
suggested that the association reflected the in situ juxtapositioning of C/EBP to nuclear matrix
proteins in isolated nuclei. The association of C/EBP with the nuclear matrix resisted RNase
and DNase treatment and extraction with protein sulfhydryl reducing agents combined with
high ionic strength salt. C/EBP displayed a proclivity to extensively reassemble with the
filament-forming nuclear matrix proteins after a cycle of solubilization with urea, followed by its
removal by dialysis. These findings suggest that the C/EBP moieties were anchored to the
nuclear matrix through hydrophobic protein-protein interactions with the lamins. Subsequent
separation of nuclear matrix-associated C/EBP into insoluble, reassembling, and soluble
nuclear matrix protein (SNMP) fractions after a cycle of solubilization/reassembly pointed to
the sub-partitioning of C/EBP on the nuclear matrix. DNA affinity chromatography using the
rat haptoglobin gene cis-element and SNMP revealed the binding of p35 during basal
transcription, and p35 and p30 during elevated haptoglobin gene transcription in the course of
the acute-phase (AP) response. It was concluded that the appearance of cis-element-binding p30
in the SNMP fraction resulted from its increased solubility (decreased hydrophobicity) and
inability to reassociate with the lamins during urea removal. The observed solubility partitioning
of C/EBP on the nuclear matrix framework could represent a level of control of the general
availability of regulatory proteins for establishing interactions with DNA.
Ključne reči:
Acute phase (AP) response; CCAAT/enhancer-binding proteins (C/EBP) α and β; Haptoglobin gene; Lamins A/C; Nuclear matrixIzvor:
Cell Biology International, 2002, 26, 5, 451-461Finansiranje / projekti:
- Tthe Research Science Fund of the Serbian Ministry of Science, Contract No. 1722
DOI: 10.1006/cbir.2002.0888
ISSN: 1065-6995
PubMed: 12095231