Expression of the E2F and retinoblastoma families of proteins during neural differentiation.
Development of the brain is determined by a strictly orchestrated program of proliferation, migration, apoptosis, differentiation, synaptogenesis, tract formation, and myelination. The E2F family of transcription factors, whose activity and functions are regulated in large part through interactions with the retinoblastoma (Rb) family of tumor suppressor proteins, has been implicated as a key regulator of proliferation, differentiation, and apoptosis in a variety of tissues. We have examined levels of the E2F and Rb families of proteins during both brain development and neural differentiation of P19 cells, and found the expression profiles during these two processes of neural development and maturation to be quite similar, i.e., strong up-regulation of p130, pronounced down-regulation of p107, moderate up-regulation of pRb, and significant down-regulation of most species of E2F and dimerization protein (DP). However, several specific isoforms, namely a 30 kDa form of DP-2, a 57 kDa species of E2F-3, a 59 kDa form of E2F-5 and the isoforms of E2F-1 recognized by the E2F-1 (KH-95) antibody were up-regulated suggesting that these particular isoforms of E2F and DP play a tissue-specific function in differentiation and maturation of nervous tissue. The potential role of the E2F/DP family of transcription factors in aspects of neural development and differentiation are considered.
Department of Molecular, Cellular and Craniofacial Biology, ULSD, University of Louisville, Birth Defects Center, Louisville, KY, USA.
J C
JC
Kusek
R M
RM
Greene
M M
MM
Pisano
D000818:Animals; D001921:Brain / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000378:metabolism; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; D050699:E2F3 Transcription Factor; D050700:E2F5 Transcription Factor; D004622:Embryo, Mammalian; D005260:Female; D008297:Male; D051379:Mice; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D016160:Retinoblastoma Protein / Q000378:metabolism*; D056465:Retinoblastoma-Binding Protein 1; D050680:Transcription Factor DP1; D014157:Transcription Factors / Q000378:metabolism*; D014404:Tubulin / Q000378:metabolism
C533431:Arid4a protein, mouse; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; D050699:E2F3 Transcription Factor; D050700:E2F5 Transcription Factor; C493754:E2f1 protein, mouse; D016160:Retinoblastoma Protein; D056465:Retinoblastoma-Binding Protein 1; C490579:Tfdp2 protein, mouse; D050680:Transcription Factor DP1; D014157:Transcription Factors; D014404:Tubulin