Cloning and developmental expression of Xenopus Stat1.
Proteins of the STAT family (Signal Transducers and Activators of Transcription) are latent cytoplasmic factors which, upon phosphorylation, are translocated to the nucleus where they participate in gene activation. In this report, we describe the cloning and developmental expression of a Xenopus homolog of Stat1. XStat1 is highly conserved, exhibiting greater than 90% identity in the critical DNA binding, SH2, SH3 and trans-activation domains with both human and murine Stat1. Using RT-PCR, we show that XStat1 is present as a maternal message during early development of Xenopus. The maternal message is translated during cleavage and its product is phosphorylated on tyrosine, a prerequisite for functional activation. During cleavage and gastrula stages, XStat1 is widely expressed throughout the developing embryo. During neurulation and early tailbud stages, XStat1 is expressed in both dorsal axial and ventral tissues. By late tailbud, dorsal XStat1 expression domains are associated with the developing pharyngeal arches and pronephros. These regions of the embryo correspond to the future location of the thymus, sites of dorsal hematopoietic activity, and one location where melanocytes differentiate.
Turpen
J B
JB
Department of Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198-6395, USA. jturpen@unmc.edu
Carlson
D L
DL
Huang
C
C
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D016384:Consensus Sequence; D017124:Conserved Sequence; D017931:DNA Primers / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D017403:In Situ Hybridization; D051379:Mice; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050794:STAT1 Transcription Factor; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000235:genetics*; D015533:Transcriptional Activation; D014981:Xenopus / Q000196:embryology / Q000235:genetics* / Q000254:growth & development; D029867:Xenopus Proteins
D017931:DNA Primers; D004268:DNA-Binding Proteins; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; C494082:Stat1 protein, Xenopus; C494080:Stat1 protein, mouse; D015534:Trans-Activators; D029867:Xenopus Proteins