A Novel Link between Integrins, Transmembrane-4 Superfamily Proteins (CD63 and CD81), and Phosphatidylinositol 4-Kinase

doi:10.1074/jbc.272.5.2595

A Novel Link between Integrins, Transmembrane-4 Superfamily Proteins (CD63 and CD81), and Phosphatidylinositol 4-Kinase*

From the^‡ Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115 and
the^¶ Division of Signal Transduction, Beth Israel Hospital and the Departments of Cell Biology and Medicine, Harvard Medical School, Boston, Massachusetts 02115

^‡‡ To whom correspondence should be addressed. Tel.: 617-632-3410; Fax: 617-632- E-mail: Martin_Hemler{at}DFCI.HARVARD.EDU.

Abstract

Enzymatic and immunochemical assays show a phosphatidylinositol 4-kinase in novel and specific complexes with proteins (CD63 and CD81) of the transmembrane 4 superfamily (TM4SF) and an integrin (α₃β₁). The size (55 kDa) and other properties of the phosphatidylinositol 4-kinase (PI 4-K) (stimulated by nonionic detergent, inhibited by adenosine, inhibited by monoclonal antibody 4CG5) are consistent with PI 4-K type II. Not only was PI 4-K associated with α₃β₁-CD63 complexes in α₃-transfected K562 cells, but also it could be co-purified from CD63 in untransfected K562 cells lacking α₃β₁. Thus, TM4SF proteins may link PI 4-K activity to the α₃β₁ integrin. The α₅β₁ integrin, which does not associate with TM4SF proteins, was not associated with PI 4-K. Notably, α₃β₁-CD63-CD81-PI 4-K complexes are located in focal complexes at the cell periphery rather than in focal adhesions. The novel linkage between integrins, transmembrane 4 proteins, and phosphoinositide signaling at the cell periphery may play a key role in cell motility and provides a signaling pathway distinct from conventional integrin signaling through focal adhesion kinase.

Footnotes

↵^§ Recipient of a Lady Tata Memorial Trust Fellowship. Present address: University of Birmingham, CRC Institute for Cancer Studies, Edgbaston, Birmingham B15 2TJ, UK.
↵^∥ Recipient of Ryan Fellowship
↵** Supported by the Lucille P. Markey Charitable Trust.
↵* This work was supported by Grants GM38903 (to M. E. H.) and GM54387 (to C. L. C.) from the National Institutes of Health. The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵¹ The abbreviations used are:

FAK

focal adhesion kinase

PI 4-K

phosphatidylinositol 4-kinase

PI 3-K

phosphatidylinositol 3-kinase

TM4SF

transmembrane-4 superfamily

mAb

monoclonal antibody

PtdIns

phosphatidylinositol

PIP

phosphatidylinositol phosphate

PIP₂

phosphatidylinositol diphosphate

PIP₃

phosphatidylinositol triphosphate

HPLC

high pressure liquid chromatography

CHAPS

3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonic acid.
↵² F. Berditchevski, S. Chang, and M. E. Hemler, manuscript in preparation.
↵³ I. Tachibana, F. Berditchevski, J. Bodorova, and M. E. Hemler, manuscript in preparation.
- Received September 17, 1996.
- Revision received November 13, 1996.