Molecular investigation of the functional relevance of missense variants of ICAM-1.
In genome-wide studies, the intercellular adhesion molecule-1 (ICAM-1) locus has been associated with cardiovascular and inflammatory bowel diseases. To determine the functional relevance of five missense ICAM-1 variants (G241R; I316V; P352L; K469E; R478W), we generated wild-type and variant proteins [M2(241R); M3(469E); M4(352L); M5(478W); M6(316V); M7(352L/469E)] and transiently transfected CV1 cells. Reverse transcription PCR, western blot, and ELISA did not reveal any differences in mRNA and protein expression levels for any construct. Conversely, in pulse-chase experiments, compared with wild-type (90-120 min), M3 and M5 possessed a prolonged half-life of approximately 150 min, whereas M2, M4, and M7 displayed a decreased half-life of approximately 60-75 min, implying differences in protein degradation. Our results do not indicate a major impact of missense variants on ICAM-1 biological function, even if G241R and K469E were functional in pulse-chase experiments. Whether these differences in protein stability exert measurable functional consequences needs to be elucidated further.
Vischer
Peter
P
Leibniz-Institute for Arteriosclerosis Research, University of Muenster, Muenster, Germany.
Telgmann
Ralph
R
Schmitz
Boris
B
Hasenkamp
Sandra
S
Schmidt-Petersen
Klaus
K
Beining
Katrin
K
Huge
Andreas
A
Paul
Martin
M
Amarenco
Pierre
P
Cambien
François
F
Brand
Eva
E
Brand-Herrmann
Stefan-Martin
SM
D005786:Gene Expression Regulation; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D020125:Mutation, Missense / Q000235:genetics*
D018799:Intercellular Adhesion Molecule-1