Isolation and comparative expression analysis of the Myc-regulatory proteins Mad1, Mad3, and Mnt during Xenopus development.
The Myc-Max-Mad network of transcription factors plays an essential role in many cellular processes such as proliferation, differentiation, and apoptosis. The Mad proteins heterodimerize with Max, function as transcriptional repressors, and are capable of antagonizing the transforming activity of Myc. We report on the isolation of Xmad1, Xmad3, and Xmnt, novel Xenopus genes belonging to the Mad family. We also describe their temporal and spatial expression patterns during Xenopus embryogenesis. Xmad1 expression is found primarily in cells that have undergone terminal differentiation including the notochord, floor plate, and cement gland. Xmad3 transcripts are expressed broadly throughout the central nervous system and the eye, starting at neurula stages. In contrast, Xmnt expression in the CNS was localized anteriorly and, in addition, is present in the migrating neural crest cells. This study demonstrates the Mads are expressed in specific and mostly nonoverlapping patterns, suggesting distinct roles during embryogenesis.
Department of Developmental Biochemistry, University of Goettingen, Goettingen, Germany.
Kathrin
K
Juergens
Barbara
B
Rust
Tomas
T
Pieler
Kristine A
KA
Henningfeld
D000595:Amino Acid Sequence; D000818:Animals; D018797:Cell Cycle Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D004625:Embryo, Nonmammalian / Q000378:metabolism; D005656:Fungal Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D015723:Gene Library; D008969:Molecular Sequence Data; D009928:Organ Specificity; D016271:Proto-Oncogene Proteins c-myc / Q000502:physiology*; D012097:Repressor Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D016415:Sequence Alignment; D029867:Xenopus Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D014982:Xenopus laevis
D018797:Cell Cycle Proteins; D005656:Fungal Proteins; C505428:Mnt protein, Xenopus; D016271:Proto-Oncogene Proteins c-myc; D012097:Repressor Proteins; D029867:Xenopus Proteins