In:
Developmental Dynamics, Wiley, Vol. 223, No. 2 ( 2002-02), p. 273-284
Abstract:
We show that α6 integrin function was required for normal lens cell differentiation by using an antisense construct to suppress α6 integrin expression. To elucidate the mechanism by which this integrin functions in the regulation of the lens cell differentiation process, we determined the molecular composition of α6 integrin signaling complexes at distinct stages of differentiation in vivo. Because both α6 integrin and insulin‐like growth factor‐1 (IGF‐1) have been implicated in signaling lens cell differentiation, we examined the possibility that they formed a signaling complex in the embryonic lens. Coprecipitation analysis revealed that α6 integrin/IGF‐1 receptor complexes were present and that their association was greatest in the equatorial zone, the region of the embryonic lens in which lens cells proliferate and then initiate their differentiation. These results provide in vivo support for the formation of integrin/growth factor receptor signaling complexes. We also found that extracellular signal‐regulated kinase (ERK), a downstream effector of both integrin and growth factor receptor signaling pathways, was associated with the α6 integrin signaling complexes in the embryonic lens. This result was supported by our findings that activated ERK, in addition to its nuclear location, localized to lens cell membranes in specific regions of cell‐matrix and cell–cell contact. A connection between integrin ligand engagement and ERK activation was shown in vitro after lens cell attachment to laminin. These results demonstrate that α6 integrin function is required for the early stages of lens cell differentiation most likely through its association with the IGF‐1 receptor and the activation of ERK. © 2002 Wiley‐Liss, Inc.
Type of Medium:
Online Resource
ISSN:
1058-8388
,
1097-0177
Language:
English
Publisher:
Wiley
Publication Date:
2002
detail.hit.zdb_id:
1473797-8
SSG:
12
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