A simple and precise method (Y2H-in-frame-seq) improves yeast two-hybrid screening with cDNA libraries

By yeast two-hybrid screening, we found three novel interactors (UNC-95, LIM-8, and LIM-9) for UNC-97/PINCH in Caenorhabditis elegans. All three proteins contain LIM domains that are required for binding. Among the three interactors, LIM-8 and LIM-9 also bind to UNC-96, a component of sarcomeric M-lines. UNC-96 and LIM-8 also bind to the C-terminal portion of a myosin heavy chain (MHC), MHC A, which resides in the middle of thick filaments in the proximity of M-lines. All interactions identified by yeast two-hybrid assays were confirmed by in vitro binding assays using purified proteins. All three novel UNC-97 interactors are expressed in body wall muscle and by antibodies localize to M-lines. Either a decreased or an increased dosage of UNC-96 results in disorganization of thick filaments. Our previous studies showed that UNC-98, a C2H2 Zn finger protein, acts as a linkage between UNC-97, an integrin-associated protein, and MHC A in myosin thick filaments. In this study, we demonstrate another mechanism by which this linkage occurs: from UNC-97 through LIM-8 or LIM-9/UNC-96 to myosin.

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Specific inhibition of transcriptional activity of the constitutive androstane receptor (CAR) by the splicing factor SF3a3

Biological Chemistry ◽

10.1515/bc.2008.149 ◽

2008 ◽

Vol 389 (10) ◽

Cited By ~ 1

Author(s):

Hye Jin Yun ◽

Jungsun Kwon ◽

Wongi Seol

Keyword(s):

Transcriptional Activity ◽

Constitutive Androstane Receptor ◽

Splicing Factor ◽

Yeast Two Hybrid ◽

Interacting Protein ◽

Functional Studies ◽

Reporter Activity ◽

Inhibitory Function ◽

Two Hybrid ◽

Hybrid Screening

Abstract The constitutive androstane receptor (CAR) is a member of the nuclear receptor superfamily and plays an important role in the degradation of xenobiotics in the liver. Using yeast two-hybrid screening, we identified SF3a3, a 60-kDa subunit of the splicing factor 3a complex, as a specific CAR-interacting protein. We further confirmed their interaction by both co-immunoprecipitation and GST pull-down assay. Functional studies showed that overexpression of SF3a3 inhibited the reporter activity driven by a promoter containing CAR binding sequences by up to 50%, whereas reduced expression of SF3a3 activated the same reporter activity by approximately three-fold. The inhibitory function of SF3a3 is independent of the presence of TCPOBOP, a CAR ligand. These data suggest that SF3a3 functions as a co-repressor of CAR transcriptional activity, in addition to its canonical function.

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Yeast Two-Hybrid Screening for Proteins that Interact with Nuclear Hormone Receptors

Steroid Receptor Methods ◽

10.1385/1-59259-115-9:227 ◽

2003 ◽

pp. 227-248 ◽

Cited By ~ 3

Author(s):

Bertrand Le Douarin ◽

David M. Heery ◽

Claudine Gaudon ◽

Elmar vom Baur ◽

Régine Losson

Keyword(s):

Hormone Receptors ◽

Nuclear Hormone Receptors ◽

Yeast Two Hybrid ◽

Two Hybrid ◽

Hybrid Screening

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Abstract 3600: HspA12B Promotes Angiogenesis through Suppressing AKAP12 and Up-Regulating VEGF Pathway

Circulation ◽

10.1161/circ.118.suppl_18.s_449 ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Rebecca J Steagall ◽

Fang Hua ◽

Mahesh Thirunazukarasu ◽

Lijun Zhan ◽

Chuanfu Li ◽

...

Keyword(s):

Cancer Metastasis ◽

Yeast Two Hybrid ◽

Vegf Expression ◽

Tubule Formation ◽

Interacting Protein ◽

Over Expression ◽

Vegf Pathway ◽

Two Hybrid ◽

Hybrid Screening

We have previously shown that HspA12B, a member of HspA70 family subfamily 12, is a novel angiogenesis regulator that is preferentially expressed in endothelial cells (ECs) and required for angiogenesis in vitro . The mechanism by which HspA12B regulates angiogenesis, however, is unknown. In this study we identified AKAP12/SSeCKS as a HSPA12B-interacting protein through a yeast two-hybrid screening and confirmed the interaction by co-immunoprecipitation and co-localization. We observed that HspA12B negatively regulated the expression of AKAP12/SSeCKS, a cancer metastasis repressor that inhibits VEGF expression and angiogen-esis. In HUVEC, HspA12B knockdown increased AKAP12 levels, decreased VEGF by more than 75%, and down-regulated Akt and pAkt; whereas HspA12B over expression decreased AKAP12 and more than doubled VEGF levels. We further identified a 32-AA domain in AKAP12 that was capable of interacting with HspA12B. Overexpression of this 32-AA domain in HUVEC disrupted the HspA12B-AKAP12 interaction and decreased VEGF expression by more than 70%, suggesting the importance of HspA12B-AKAP12 interaction in regulating VEGF. We also observed that HspA12B expression was increased more than 2 folds in ECs by hypoxia or shearing stress, and induced in ischemic rat heart. Inhibition of HspA12B abolished hypoxia-induced tubule formation. Adeno-HspA12B promoted angiogenesis in DIVAA assay. We concluded that this is the first evidence that HspA12B promotes angiogenesis through regulating VEGF by way of suppressing AKAP12. Our finding is the first example of an EC-specific molecular chaperone acting as the regulator of angiogenesis.

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