Biology Reference
In-Depth Information
Integrin (QD605)
Caveolin-1
(Alexa488)
Merge
Antibody-induced clustering of
α β
2 1
integrin for 2 h
Fig. 2.
1 cells under normal condi-
tions. (
A
) and after antibody-induced cross-linking (
B
). Integrin is labeled by
monoclonal antibodies followed by goat anti-mouse quantum dots 605
(Chemicon).
α
2
β
1 integrin distribution in SAOS
α
2
β
1 integrin is found on the plasma membrane in normal con-
ditions (
A
). For antibody-induced cross-linking (
B
), cells are treated here with
quantum dot secondary antibodies for 2 h at 37
α
2
β
C. After fixation, caveolin-1
is also labeled in the cells and revealed by goat anti-rabbit Alexa-488 (green).
The confocal image shows that during antibody-induced cross-linking inte-
grin accumulates very efficiently in caveolin-1 positive caveosomes in the
cytoplasm. In these images the orange color of quantum dot 605 is changed
into false color red in order to reveal the colocalization with caveolin-1 better.
Bar
°
=
10
µ
m.
I domains, for example the fibronectin receptors, bind to
their ligands with a special site partially formed by their
that have no
α
β
I domains.
21
The
β
I domain connects the integrin
α
and
β
subunits together by inter-
acting with a
β
-propeller domain in the
α
subunit. Structurally and func-
tionally integrin
I domains are very similar. A ligand-dependent
conformational change in the
α
I and
β
β Ι
domain triggers the leg parts of the
α
