Person:
TURAN, KADİR

Profile Picture

Email Address

Birth Date

Research Projects

Organizational Units

OrgUnit Logo
Organizational Unit

Job Title

Last Name

TURAN

First Name

KADİR

Name

Filters

2004 - 20062
Reset filters

Settings

End date: 2009 × Start date: 2004 ×

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    PublicationMetadata only
    Chitosan-DNA nanoparticles: The effect of cell type and hydrolysis of chitosan on in vitro DNA transfection
    (TAYLOR & FRANCIS INC, 2006) TURAN, KADİR; Turan, Kadir; Nagata, Kyosuke
    Commercial chitosan (Ch) with low (LMWCh) and medium molecular weight (MMWCh) were hydrolyzed in diluted hydrochloric acid by heating at different temperatures. The viscosity average molecular weight of Chs was gradually decreased from 450 to 14 kDa as a function of temperature. Ch fractions were used for formation of Ch-DNA nanoparticles and tested for the ability to introduce DNA into HEK293, Swiss3T3, HeLa, and MDCK cells in vitro. The average diameter of nanoparticles was 200-220 nm. The surface charge of nanoparticles varied depending on the Ch/DNA ratio. The cell lines different response to DNA transection with Ch fractions depended on molecular weight. HEK293 cells were efficiently transfected by nanoparticles prepared with Chs having a wide range of molecular weight (similar to 14-195 kDa). Swiss3T3 cells were efficiently transfected by Ch polymers with about <17 kDa. In contrast, HeLa and MDCK cells were highly resistant to DNA transfection with Ch polymers. These results strongly suggest that Ch polymers may be widely used for DNA trasnfection of the mammalian cells under optimized conditions.
  • Thumbnail Image
    PublicationOpen Access
    Nuclear MxA proteins form a complex with influenza virus NP and inhibit the transcription of the engineered influenza virus genome
    (OXFORD UNIV PRESS, 2004-01-21) TURAN, KADİR; Turan, K; Mibayashi, M; Sugiyama, K; Saito, S; Numajiri, A; Nagata, K
    Mx proteins belong to the dynamin superfamily of high molecular weight GTPases and interfere with multiplication of a wide variety of viruses. Earlier studies show that nuclear mouse Mx1 and human MxA designed to be localized in the nucleus inhibit the transcription step of the influenza virus genome. Here we set a transient influenza virus transcription system using luciferase as a reporter gene and cells expressing the three RNA polymerase subunits, PB1, PB2 and PA, and NP. We used this reporter assay system and nuclear-localized MxA proteins to get clues for elucidating the anti-influenza virus activity of MxA. Nuclear-localized VP16-MxA and MxA-TAg NLS strongly interfered with the influenza virus transcription. Over-expression of PB2 led to a slight resumption of the transcription inhibition by nuclear MxA, whereas over-expression of PB1 and PA did not affect the MxA activity. Of interest is that the inhibitory activity of the nuclear MxA was markedly neutralized by over-expression of NP. An NP devoid of its C-terminal region, but containing the N-terminal RNA binding domain, also neutralized the VP16-MxA activity in a dose-dependent manner, whereas an NP lacking the N-terminal region did not affect the VP16-MxA activity. Further, not only VP16-MxA but also the wild-type MxA was found to interact with NP in influenza virus-infected cells. This indicates that the nuclear MxA suppresses the influenza virus transcription by interacting with not only PB2 but also NP.