Regulation of embryonic hematopoiesis by a cytokine-inducible SH2 domain homolog in zebrafish.
Cytokine-inducible SH2 domain-containing protein (CISH), a member of the suppressor of cytokine signaling family of negative feedback regulators, is induced by cytokines that activate STAT5 and can inhibit STAT5 signaling in vitro. However, demonstration of a definitive in vivo role for CISH during development has remained elusive. This study employed expression analysis and morpholino-mediated knockdown in zebrafish in concert with bioinformatics and biochemical approaches to investigate CISH function. Two zebrafish CISH paralogs were identified, cish.a and cish.b, with high overall conservation (43-46% identity) with their mammalian counterparts. The cish.a gene was maternally derived, with transcripts present throughout embryogenesis, and increasing at 4-5 d after fertilization, whereas cish.b expression commenced at 8 h after fertilization. Expression of cish.a was regulated by the JAK2/STAT5 pathway via conserved tetrameric STAT5 binding sites (TTCN3GAA) in its promoter. Injection of morpholinos targeting cish.a, but not cish.b or control morpholinos, resulted in enhanced embryonic erythropoiesis, myelopoiesis, and lymphopoiesis, including a 2- 3-fold increase in erythrocytic markers. This occurred concomitantly with increased activation of STAT5. This study indicates that CISH functions as a conserved in vivo target and regulator of STAT5 in the control of embryonic hematopoiesis.
School of Life and Environmental Sciences, Deakin University, Burwood, Victoria 3125, Australia; Walter and Eliza Hall Institute for Medical Research, Parkville, Victoria 3050, Australia;
Rowena S
RS
Lewis
School of Medicine, Deakin University, Geelong, Victoria 3217, Australia; Strategic Research Centre in Molecular and Medical Research, Deakin University, Geelong, Victoria 3217, Australia; and Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
Suzita M
SM
Noor
School of Medicine, Deakin University, Geelong, Victoria 3217, Australia; Strategic Research Centre in Molecular and Medical Research, Deakin University, Geelong, Victoria 3217, Australia; and.
Fiona W
FW
Fraser
School of Medicine, Deakin University, Geelong, Victoria 3217, Australia; Strategic Research Centre in Molecular and Medical Research, Deakin University, Geelong, Victoria 3217, Australia; and.
Robert
R
Sertori
School of Medicine, Deakin University, Geelong, Victoria 3217, Australia; Strategic Research Centre in Molecular and Medical Research, Deakin University, Geelong, Victoria 3217, Australia; and.
Clifford
C
Liongue
School of Medicine, Deakin University, Geelong, Victoria 3217, Australia; Strategic Research Centre in Molecular and Medical Research, Deakin University, Geelong, Victoria 3217, Australia; and award@deakin.edu.au.
Alister C
AC
Ward
D000818:Animals; D001483:Base Sequence; D004625:Embryo, Nonmammalian / Q000276:immunology*; D006410:Hematopoiesis / Q000235:genetics / Q000276:immunology*; D053614:Janus Kinase 2 / Q000235:genetics / Q000276:immunology; D008969:Molecular Sequence Data; D050799:STAT5 Transcription Factor / Q000235:genetics / Q000276:immunology*; D050826:Suppressor of Cytokine Signaling Proteins / Q000235:genetics / Q000276:immunology*; D015027:Zebrafish / Q000235:genetics / Q000276:immunology*; D029961:Zebrafish Proteins / Q000235:genetics / Q000276:immunology*
D053614:Janus Kinase 2; D050799:STAT5 Transcription Factor; D050826:Suppressor of Cytokine Signaling Proteins; D029961:Zebrafish Proteins