An ErbB2-Muc4 complex in rat ocular surface epithelia.
OBJECTIVE
To show the presence and localization of type 1 growth factor receptors (ErbB2, ErbB3 and ErbB4) in rat corneal and conjunctival epithelia and investigate the association of ErbB2 with its intramembrane ligand Muc4.


METHODS
Methacarn-fixed, paraffin-embedded sections of corneas and eyelids from female adult rats were immunocytochemically stained using antibodies against the ErbB receptors and Muc4. Sequential immunoprecipitation and immunoblot analyses were performed on epithelial lysates to investigate the presence of a complex of Muc4 and ErbB2 in corneal and conjunctival epithelia.


RESULTS
Immunocytochemical staining demonstrated the presence of ErbB2, ErbB3 and ErbB4 growth factor receptors throughout the rat corneal and conjunctival epithelia. Co-immunoprecipitation of the epithelial lysates demonstrated that Muc4 and ErbB2 are present as a complex.


CONCLUSIONS
The three type 1 growth factor receptors (ErbB2, ErbB3 and ErbB4) are present in the rat corneal and conjunctival epithelia, and ErbB2 is at least partly associated with Muc4. This demonstration of the presence and localization of these three type 1 growth factor receptors may help in understanding how these receptors contribute to ocular epithelial behavior and functions.
Swan
Jeremy S
JS
Department of Cell Biology and Anatomy, University of Miami School of Medicine, Miami, FL, USA.
Arango
Maria E
ME
Carothers Carraway
Coralie A
CA
Carraway
Kermit L
KL
D000818:Animals; D003228:Conjunctiva / Q000378:metabolism*; D004848:Epithelium / Q000378:metabolism; D019573:Epithelium, Corneal / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism; D005260:Female; D007150:Immunohistochemistry; D055264:Mucin-4; D009077:Mucins / Q000378:metabolism*; D051381:Rats; D011916:Rats, Inbred F344; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D020893:Receptor, ErbB-3 / Q000378:metabolism; D066247:Receptor, ErbB-4
D066246:ErbB Receptors; D055264:Mucin-4; D009077:Mucins; D018719:Erb-b2 Receptor Tyrosine Kinases; D020893:Receptor, ErbB-3; D066247:Receptor, ErbB-4; C524660:Muc4 protein, rat; C587691:Erbb4 protein, rat