A pleckstrin homology-like domain is critical for F-actin binding and cofilin-phosphatase activity of Slingshot-1

Takahashi, Katsunori; Okabe, Haruka; Kanno, Shin-ichiro; Nagai, Tomoaki; Mizuno, Kensaku

doi:10.1016/j.bbrc.2016.11.095

Cited by 6 publications

(7 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although full-length Slingshot exhibited relatively low phosphatase activity toward both small artificial substrates and its physiological substrate phospho-cofilin, a dramatic increase in Slingshot activity has previously been observed following incubation with F-actin (16). The N-terminal Arg 96 , the Leu 185 -Lys 187 region, and the C-terminal Trp 457 of SSH1 were identified as being directly involved in actin binding (16,24). We therefore examined the effect of actin on the phosphatase activity of different SSH2 truncations.…”

Section: F-actin Activates Ssh2 Through Relieving Auto-inhibition By mentioning

confidence: 88%

“…Previous studies found that the N-terminal regions are required for F-actin-mediated Slingshot activation and that residues Arg 96 , Leu 185 , His 186 , Lys 187 , and Trp 457 of SSH1 may directly interact with F-actin (16,24). Our biophysical studies found that the 98-C-bimane probe underwent significant fluorescence quenching after incubation with F-actin, confirming that the loop between the ␤1 and ␤2 sheets of the predicted PH-like domain (42) is one of the critical interaction sites of Slingshot with F-actin.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Allosteric modulation of the catalytic VYD loop in Slingshot by its N-terminal domain underlies both Slingshot auto-inhibition and activation

Du¹,

Peng

et al. 2018

Journal of Biological Chemistry

View full text Add to dashboard Cite

Slingshots are phosphatases that modulate cytoskeleton dynamics, and their activities are tightly regulated in different physiological contexts. Recently, abnormally elevated Slingshot activity has been implicated in many human diseases, such as cancer, Alzheimer's disease, and vascular diseases. Therefore, Slingshot-specific inhibitors have therapeutic potential. However, an enzymological understanding of the catalytic mechanism of Slingshots and of their activation by actin is lacking. Here, we report that the N-terminal region of human Slingshot2 auto-inhibits its phosphatase activity in a noncompetitive manner. pH-dependent phosphatase assays and leaving-group dependence studies suggested that the N-terminal domain of Slingshot2 regulates the stability of the leaving group of the product during catalysis by modulating the general acid Asp in the catalytic VYD loop. F-actin binding relieved this auto-inhibition and restored the function of the general acid. Limited tryptic digestion and biophysical studies identified large conformational changes in Slingshot2 after the F-actin binding. The dissociation of N-terminal structural elements, including Leu, and the exposure of the loop between α-helix-2 and β-sheet-3 of the phosphatase domain served as the structural basis for Slingshot activation via F-actin binding and via neuregulin stimulation in cells. Moreover, we designed a FlAsH-BRET-based Slingshot2 biosensor whose readout was highly correlated with the phosphatase activities of Slingshot2. Our results reveal the auto-inhibitory mechanism and allosteric activation mechanisms of a human Slingshot phosphatase. They also contribute to the design of new strategies to study Slingshot regulation in various cellular contexts and to screen for new activators/inhibitors of Slingshot activity.

show abstract

Section: F-actin Activates Ssh2 Through Relieving Auto-inhibition By mentioning

confidence: 88%

Section: Discussionmentioning

confidence: 99%

Allosteric modulation of the catalytic VYD loop in Slingshot by its N-terminal domain underlies both Slingshot auto-inhibition and activation

Du¹,

Peng

et al. 2018

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…SSH1 dephosphorylates and activates cofilin, which is a member of the actin-depolymerizing factor/cofilin family of proteins [ 12 , 17 ] that regulates formation of the actin cytoskeleton. Tumour invasion and metastasis, the main causes of cancer-related death, are directly associated with cofilin activity [ 18 , 19 ].…”

Section: Discussionmentioning

confidence: 99%

SSH1 expression is associated with gastric cancer progression and predicts a poor prognosis

Maimaiti

Maimaitiming

et al. 2018

BMC Gastroenterol

View full text Add to dashboard Cite

BackgroundSlingshot homolog-1 (SSH1) plays an important role in pathological processes, including in the occurrence and development of tumours. The purpose of this study was to determine whether SSH1 is a key biomarker with prognostic value for survival in patients with gastric cancer.MethodsWe performed immunohistochemistry (IHC) on tissue microarrays containing 100 gastric cancer specimens to evaluate SSH1 protein expression. The association of pathological characteristics with cumulative survival was determined by Kaplan-Meier analysis. A Cox proportional hazards model was generated in the multi-factorial survival analysis to identify univariate prognostic factors of GC.ResultsSSH1 expression level in gastric cancer tissues was significantly associated with lymph node metastasis (P = 0.032). Additionally, multivariate regression analysis clearly indicated that SSH1 expression was significantly correlated with poor clinical outcomes of patients with gastric cancer (P = 0.016). Multivariate analyses showed that SSH1 was the best predictor of poor prognosis in patients with gastric cancer (P = 0.030).ConclusionsSSH1 expression is associated with gastric cancer progression and predicts a poor prognosis. SSH1 may play an important role in the development of gastric cancer, and it is a promising target for prevention and/or treatment of gastric cancer.

show abstract

“…The cofilin-phosphatase activity of SSH-1L is increased by binding to F-actin [ 30 – 32 ] via Trp-458 at the C-terminus of the phosphatase domain and the N-terminal LHK and C-terminal LKR motifs. A pleckstrin homology-like domain at the N-terminus of SSH-1L was also shown to be involved in F-actin binding and cofilin phosphatase activity [ 33 ].…”

Section: Discussionmentioning

confidence: 99%

Slingshot-1L, a cofilin phosphatase, induces primary breast cancer metastasis

et al. 2017

View full text Add to dashboard Cite

Slingshot (SSH) is a member of the conserved family of cofilin phosphatases that plays a critical role in cell membrane protrusion and migration by transforming inactive phosphorylated cofilin to an active form. SSH-like protein 1 (SSH-1L) expression is detected in various types of tumors; insulin induces the phosphatases activity of SSH-1L in a phosphoinositide 3-kinase-dependent manner. However, little is known about the expression and role of SSH-1L in breast cancer. Here, we analyzed 295 human breast cancer tissue specimens for SSH-1L expression by immunohistochemistry. The correlation between SSH-1L level and patients’ clinical characteristics was analyzed with Pearson’s χ2 test. The function of SSH-1L was evaluated by gene knockdown and quantitative real-time polymerase chain reaction detection of cofilin expression in MDA-MB-231, MCF-7, and SK-BR-3 human breast cancer cell lines. SSH-1L expression was detected in 88.1% of tissue specimens by immunohistochemistry and was strongly associated with increased metastasis and mortality. Loss of SSH-1L expression decreased the nonphosphorylated, active form of cofilin in SK-BR-3 and MDA-MB-231 cell lines, which was associated with reduced cell motility. Accordingly, SSH-1L/cofilin signaling played a critical role in primary breast cancer metastasis and was a potential therapeutic target for breast cancer treatment.

show abstract

A pleckstrin homology-like domain is critical for F-actin binding and cofilin-phosphatase activity of Slingshot-1

Cited by 6 publications

References 21 publications

Allosteric modulation of the catalytic VYD loop in Slingshot by its N-terminal domain underlies both Slingshot auto-inhibition and activation

Allosteric modulation of the catalytic VYD loop in Slingshot by its N-terminal domain underlies both Slingshot auto-inhibition and activation

SSH1 expression is associated with gastric cancer progression and predicts a poor prognosis

Slingshot-1L, a cofilin phosphatase, induces primary breast cancer metastasis

Contact Info

Product

Resources

About