title: The new face of the old molecules: crustin Pm4 and transglutaminase type I serving as rnps down-regulate astakine-mediated hematopoiesis.
abstract: Astakine is an important cytokine that is involved in crustacean hematopoiesis. Interestingly, the protein levels of astakine increased dramatically in plasma of LPS-injected shrimp while mRNA levels remained unchanged. Here, we investigated the involvement of astakine 3'-untranslated region (UTR) in its protein expression. The 3'-UTR of astakine down-regulated the expression of reporter protein but the mRNA stability of reporter gene was unaffected. We identified the functional regulatory elements of astakine 3'-UTR, where 3'-UTR242-483 acted as repressor. The electrophoresis mobility shift assay (EMSA), RNA pull-down assay and LC/MS/MS were performed to identify the protein association. We noted that crustin Pm4 and shrimp transglutaminase I (STG I) were associated to astakine 3'-UTR242-483, while two other proteins have yet to be revealed. Depletion of hemocytic crustin Pm4 and STG I significantly increased the protein level of astakine while astakine mRNA level remained unaffected. Lipopolysaccharide (LPS) stimulated the secretion of crustin Pm4 and STG I from hemocytes to plasma and increased the astakine level to stimulate the hemocytes proliferation. Altogether, we identified the shrimp crustin Pm4 and STG I as novel RNA binding proteins that play an important role in down-regulating astakine expression at post-transcriptional level and are crucial for the maintenance of hematopoiesis.
authors.affiliation: Institute of Zoology, National Taiwan University, Taipei, Taiwan, ROC.
authors.forename: Yun-Tsan
authors.initials: YT
authors.lastname: Chang
authors.forename: Cheng-Yung
authors.initials: CY
authors.lastname: Lin
authors.forename: Che-Yiang
authors.initials: CY
authors.lastname: Tsai
authors.forename: Vinu S
authors.initials: VS
authors.lastname: Siva
authors.forename: Chia-Ying
authors.initials: CY
authors.lastname: Chu
authors.forename: Huai-Jen
authors.initials: HJ
authors.lastname: Tsai
authors.forename: Yen-Ling
authors.initials: YL
authors.lastname: Song
mesh_terms: D020413:3' Untranslated Regions / Q000502:physiology; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000235:genetics / Q000378:metabolism*; D060829:Arthropod Proteins / Q000235:genetics / Q000378:metabolism*; D033364:Decapoda / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation / Q000502:physiology*; D006410:Hematopoiesis / Q000502:physiology*; D006434:Hemocytes / Q000166:cytology / Q000378:metabolism; D020871:RNA Stability / Q000502:physiology; D012261:Ribonucleoproteins / Q000235:genetics / Q000378:metabolism*; D061987:Sf9 Cells; D018411:Spodoptera; D011503:Transglutaminases / Q000235:genetics / Q000378:metabolism*; D042662:Vascular Endothelial Growth Factor, Endocrine-Gland-Derived / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D020413:3' Untranslated Regions; D023181:Antimicrobial Cationic Peptides; D060829:Arthropod Proteins; D012261:Ribonucleoproteins; D042662:Vascular Endothelial Growth Factor, Endocrine-Gland-Derived; D011503:Transglutaminases; C105804:transglutaminase 1