The role of the CPNKEKEC sequence in the β2 subunit I domain in regulation of integrin αLβ2 (LFA-1)

Tetsuji Kamata, Kenneth Khiem Tieu, Takehiko Tarui, Wilma Puzon-McLaughlin, Nancy Hogg, Yoshikazu Takada

Research output: Contribution to journalArticle

41 Citations (Scopus)

Abstract

The αL I (inserted or interactive) domain of integrin αLβ2 undergoes conformational changes upon activation. Recent studies show that the isolated, activated αL I domain is sufficient for strong ligand binding, suggesting the β2 subunit to be only indirectly involved. It has been unclear whether the activity of the αL I domain is regulated by the β2 subunit. In this study, we demonstrate that swapping the disulfide-linked CPNKEKEC sequence (residues 169-176) in the β2 I domain with a corresponding β3 sequence, or mutating Lys174 to Thr, constitutively activates αLβ2 binding to ICAM-1. These mutants do not require Mn2+ for ICAM-1 binding and are insensitive to the inhibitory effect of Ca2+. We have also localized a component of the mAb 24 epitope (a reporter of β2 integrin activation) in the CPNKEKEC sequence. Glu173 and Glu175 of the β2 I domain are identified as critical for mAb 24 binding. Because the epitope is highly expressed upon β2 integrin activation, it is likely that the CPNKEKEC sequence is exposed or undergoes conformational changes upon activation. Deletion of the αL I domain did not eliminate the mAb 24 epitope. This confirms that the αL I domain is not critical for mAb 24 binding, and indicates that mAb 24 detects a change expressed in part in the β2 subunit I domain. These results suggest that the CPNKEKEC sequence of the β2 I domain is involved in regulating the αL I domain.

Original languageEnglish
Pages (from-to)2296-2301
Number of pages6
JournalJournal of Immunology
Volume168
Issue number5
Publication statusPublished - Mar 1 2002
Externally publishedYes

Fingerprint

Lymphocyte Function-Associated Antigen-1
Integrins
Epitopes
Intercellular Adhesion Molecule-1
Disulfides
Ligands

ASJC Scopus subject areas

  • Immunology

Cite this

Kamata, T., Tieu, K. K., Tarui, T., Puzon-McLaughlin, W., Hogg, N., & Takada, Y. (2002). The role of the CPNKEKEC sequence in the β2 subunit I domain in regulation of integrin αLβ2 (LFA-1). Journal of Immunology, 168(5), 2296-2301.

The role of the CPNKEKEC sequence in the β2 subunit I domain in regulation of integrin αLβ2 (LFA-1). / Kamata, Tetsuji; Tieu, Kenneth Khiem; Tarui, Takehiko; Puzon-McLaughlin, Wilma; Hogg, Nancy; Takada, Yoshikazu.

In: Journal of Immunology, Vol. 168, No. 5, 01.03.2002, p. 2296-2301.

Research output: Contribution to journalArticle

Kamata, T, Tieu, KK, Tarui, T, Puzon-McLaughlin, W, Hogg, N & Takada, Y 2002, 'The role of the CPNKEKEC sequence in the β2 subunit I domain in regulation of integrin αLβ2 (LFA-1)', Journal of Immunology, vol. 168, no. 5, pp. 2296-2301.
Kamata T, Tieu KK, Tarui T, Puzon-McLaughlin W, Hogg N, Takada Y. The role of the CPNKEKEC sequence in the β2 subunit I domain in regulation of integrin αLβ2 (LFA-1). Journal of Immunology. 2002 Mar 1;168(5):2296-2301.
Kamata, Tetsuji ; Tieu, Kenneth Khiem ; Tarui, Takehiko ; Puzon-McLaughlin, Wilma ; Hogg, Nancy ; Takada, Yoshikazu. / The role of the CPNKEKEC sequence in the β2 subunit I domain in regulation of integrin αLβ2 (LFA-1). In: Journal of Immunology. 2002 ; Vol. 168, No. 5. pp. 2296-2301.
@article{1b46c033ea7848bab18741219a53db4f,
title = "The role of the CPNKEKEC sequence in the β2 subunit I domain in regulation of integrin αLβ2 (LFA-1)",
abstract = "The αL I (inserted or interactive) domain of integrin αLβ2 undergoes conformational changes upon activation. Recent studies show that the isolated, activated αL I domain is sufficient for strong ligand binding, suggesting the β2 subunit to be only indirectly involved. It has been unclear whether the activity of the αL I domain is regulated by the β2 subunit. In this study, we demonstrate that swapping the disulfide-linked CPNKEKEC sequence (residues 169-176) in the β2 I domain with a corresponding β3 sequence, or mutating Lys174 to Thr, constitutively activates αLβ2 binding to ICAM-1. These mutants do not require Mn2+ for ICAM-1 binding and are insensitive to the inhibitory effect of Ca2+. We have also localized a component of the mAb 24 epitope (a reporter of β2 integrin activation) in the CPNKEKEC sequence. Glu173 and Glu175 of the β2 I domain are identified as critical for mAb 24 binding. Because the epitope is highly expressed upon β2 integrin activation, it is likely that the CPNKEKEC sequence is exposed or undergoes conformational changes upon activation. Deletion of the αL I domain did not eliminate the mAb 24 epitope. This confirms that the αL I domain is not critical for mAb 24 binding, and indicates that mAb 24 detects a change expressed in part in the β2 subunit I domain. These results suggest that the CPNKEKEC sequence of the β2 I domain is involved in regulating the αL I domain.",
author = "Tetsuji Kamata and Tieu, {Kenneth Khiem} and Takehiko Tarui and Wilma Puzon-McLaughlin and Nancy Hogg and Yoshikazu Takada",
year = "2002",
month = "3",
day = "1",
language = "English",
volume = "168",
pages = "2296--2301",
journal = "Journal of Immunology",
issn = "0022-1767",
publisher = "American Association of Immunologists",
number = "5",

}

TY - JOUR

T1 - The role of the CPNKEKEC sequence in the β2 subunit I domain in regulation of integrin αLβ2 (LFA-1)

AU - Kamata, Tetsuji

AU - Tieu, Kenneth Khiem

AU - Tarui, Takehiko

AU - Puzon-McLaughlin, Wilma

AU - Hogg, Nancy

AU - Takada, Yoshikazu

PY - 2002/3/1

Y1 - 2002/3/1

N2 - The αL I (inserted or interactive) domain of integrin αLβ2 undergoes conformational changes upon activation. Recent studies show that the isolated, activated αL I domain is sufficient for strong ligand binding, suggesting the β2 subunit to be only indirectly involved. It has been unclear whether the activity of the αL I domain is regulated by the β2 subunit. In this study, we demonstrate that swapping the disulfide-linked CPNKEKEC sequence (residues 169-176) in the β2 I domain with a corresponding β3 sequence, or mutating Lys174 to Thr, constitutively activates αLβ2 binding to ICAM-1. These mutants do not require Mn2+ for ICAM-1 binding and are insensitive to the inhibitory effect of Ca2+. We have also localized a component of the mAb 24 epitope (a reporter of β2 integrin activation) in the CPNKEKEC sequence. Glu173 and Glu175 of the β2 I domain are identified as critical for mAb 24 binding. Because the epitope is highly expressed upon β2 integrin activation, it is likely that the CPNKEKEC sequence is exposed or undergoes conformational changes upon activation. Deletion of the αL I domain did not eliminate the mAb 24 epitope. This confirms that the αL I domain is not critical for mAb 24 binding, and indicates that mAb 24 detects a change expressed in part in the β2 subunit I domain. These results suggest that the CPNKEKEC sequence of the β2 I domain is involved in regulating the αL I domain.

AB - The αL I (inserted or interactive) domain of integrin αLβ2 undergoes conformational changes upon activation. Recent studies show that the isolated, activated αL I domain is sufficient for strong ligand binding, suggesting the β2 subunit to be only indirectly involved. It has been unclear whether the activity of the αL I domain is regulated by the β2 subunit. In this study, we demonstrate that swapping the disulfide-linked CPNKEKEC sequence (residues 169-176) in the β2 I domain with a corresponding β3 sequence, or mutating Lys174 to Thr, constitutively activates αLβ2 binding to ICAM-1. These mutants do not require Mn2+ for ICAM-1 binding and are insensitive to the inhibitory effect of Ca2+. We have also localized a component of the mAb 24 epitope (a reporter of β2 integrin activation) in the CPNKEKEC sequence. Glu173 and Glu175 of the β2 I domain are identified as critical for mAb 24 binding. Because the epitope is highly expressed upon β2 integrin activation, it is likely that the CPNKEKEC sequence is exposed or undergoes conformational changes upon activation. Deletion of the αL I domain did not eliminate the mAb 24 epitope. This confirms that the αL I domain is not critical for mAb 24 binding, and indicates that mAb 24 detects a change expressed in part in the β2 subunit I domain. These results suggest that the CPNKEKEC sequence of the β2 I domain is involved in regulating the αL I domain.

UR - http://www.scopus.com/inward/record.url?scp=0036499161&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0036499161&partnerID=8YFLogxK

M3 - Article

C2 - 11859118

AN - SCOPUS:0036499161

VL - 168

SP - 2296

EP - 2301

JO - Journal of Immunology

JF - Journal of Immunology

SN - 0022-1767

IS - 5

ER -