Differential cytoskeletal association of ErbB1 and ErbB2 during keratinocyte differentiation.
ErbB1 and ErbB2 display differential subcellular localization in human skin and cultured keratinocytes. To determine whether ErbB1 and ErbB2 also differ in cytoskeletal binding properties, normal human keratinocytes grown under conditions favoring a basal or differentiated phenotype were repeatedly extracted in a non-ionic detergent buffer. In basaloid keratinocytes, cytoskeletal association of ErbB1 and ErbB2 was limited. ErbB1 ( approximately 5%) was tightly associated with the cytoskeleton, compared to <1% of ErbB2 (p=0.004). After EGF stimulation, activated ErbB1 and ERK associated with the cytoskeleton to a greater extent than did total ErbB1 and total ERK. Association of ErbB2 increased markedly in differentiated keratinocytes, whereas association of ErbB1 was similar in basaloid and differentiated cells. Cytoskeletal association of ErbB2 correlated with plasma membrane localization. These results suggest that ErbB1 and ErbB2 employ different mechanisms of plasma membrane targeting during keratinocyte differentiation, and that cytoskeletal association may facilitate the coupling of activated ErbB1 and ERK.
Department of Dermatology, University of Michigan Medical Center, 1500 East Medical Center Drive, 3312 CCGC, P.O. Box 0932, Ann Arbor, MI 48109-0932, USA.
Sanjay
S
Kansra
Stefan W
SW
Stoll
James T
JT
Elder
D002138:Calibration; D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D003599:Cytoskeleton / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000378:metabolism; D066246:ErbB Receptors / Q000378:metabolism*; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D010766:Phosphorylation; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D013347:Subcellular Fractions; D014443:Tyrosine / Q000378:metabolism
D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D020928:Mitogen-Activated Protein Kinases; D018719:Erb-b2 Receptor Tyrosine Kinases; D014443:Tyrosine