Type II phosphatidylinositol phosphate kinases (PIPkins) have recently been found to be primarily phosphatidylinositol 5-phosphate 4-kinases, and their physiological role remains unclear. We have previously shown that a Type II PIPkin [isoform(s) unknown], is localized partly in the nucleus [Divecha, Rhee, Letcher and Irvine (1993) Biochem. J. 289, 617-620], and here we show, by transfection of HeLa cells with green-fluorescent-protein-tagged Type II PIPkins, that this is likely to be the Type IIβ isoform. Type IIβ PIPkin has no obvious nuclear localization sequence, and a detailed analysis of the localization of chimaeras and mutants of the α (cytosolic) and β PIPkins shows that the nuclear localization requires the presence of a 17-amino-acid length of α-helix (α-helix 7) that is specific to the β isoform, and that this helix must be present in its entirety, with a precise orientation. This resembles the nuclear targeting of the HIV protein Vpr, and Type IIβ PIPkin is apparently therefore the first example of a eukaryotic protein that uses the same mechanism.
Skip Nav Destination
Article navigation
March 2000
-
Cover Image
Cover Image
- PDF Icon PDF LinkFront Matter
- PDF Icon PDF LinkTable of Contents
Research Article|
March 07 2000
Nuclear targeting of the β isoform of Type II phosphatidylinositol phosphate kinase (phosphatidylinositol 5-phosphate 4-kinase) by its α-helix 7
Antonio CIRUELA;
Antonio CIRUELA
1
*Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QJ, U.K.
Search for other works by this author on:
Katherine A. HINCHLIFFE;
Katherine A. HINCHLIFFE
*Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QJ, U.K.
Search for other works by this author on:
Nullin DIVECHA;
Nullin DIVECHA
†The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, The Netherlands
Search for other works by this author on:
Robin F. IRVINE
Robin F. IRVINE
2
*Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QJ, U.K.
2To whom correspondence should be addressed (e-mail rfi20@cam.ac.uk).
Search for other works by this author on:
Publisher: Portland Press Ltd
Received:
November 15 1999
Revision Received:
December 14 1999
Accepted:
January 10 2000
Online ISSN: 1470-8728
Print ISSN: 0264-6021
The Biochemical Society, London © 2000
2000
Biochem J (2000) 346 (3): 587–591.
Article history
Received:
November 15 1999
Revision Received:
December 14 1999
Accepted:
January 10 2000
Citation
Antonio CIRUELA, Katherine A. HINCHLIFFE, Nullin DIVECHA, Robin F. IRVINE; Nuclear targeting of the β isoform of Type II phosphatidylinositol phosphate kinase (phosphatidylinositol 5-phosphate 4-kinase) by its α-helix 7. Biochem J 15 March 2000; 346 (3): 587–591. doi: https://doi.org/10.1042/bj3460587
Download citation file:
Sign in
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Captcha Validation Error. Please try again.