Objective To summarize the traits of calcium-binding tyrosine phosphorylation regulate gene and the significance in tumor incidence. Methods The domestic and foreign literatures about calcium-binding tyrosine phosphorylation regulate gene involved in the regulation of signaling pathways and research status in a variety of tumors were reviewed. Results Calcium-binding tyrosine phosphorylation regulate gene induced the abnormal proliferation of cells through multiple mechanisms. There was closely relation between the occurrence of many tumors and abnormal expression of calcium-binding tyrosine phosphorylation regulate gene. In the distribution of different epithelial tumors， the pathway of calcium-binding tyrosine phosphorylation regulate gene involved in the regulation was same， and the effect target was similar. Conclusion Further study of the calcium-binding tyrosine phosphorylation regulate gene is expected to provide a new way for clarify the occurrence and development mechanisms of tumors， and can serve as important means of early diagnosis and adjuvant therapy.
The aim of this study is to determine the regulatory mechanism of PTEN-induced putative kinase protein 1 short isoform (PINK1S) in cytoplasm. By co-immunoprecipitation (Co-IP) assay, we identified that PINK1S interacted with the beta regulatory subunit of Casein Kinase 2 (CK2β), but not with the catalytic subunits CK2α1 and CK2α2. Furthermore, cells were transfected with PINK1S and CK2β, and then PINK1S was purified by immunoprecipitation. After detecting the phosphorylated proteins by Phos-tagTM Biotin, we found that CK2β overexpression increased auto-phosphorylation of PINK1S. Finally, we generated CK2β knockdown cell lines by RNA interference. Purified PINK1S from CK2β knockdown cells significantly reduced its auto-phosphorylation compared with control cells. These results suggested that CK2β functions as a regulatory subunit of PINK1S kinase complex promoted its activation by self-phosphorylation.
The intracellular domain of clusters of differentiation 44 (CD44) binding to the FERM (protein 4.1-ezrin-radixin-moesin) domain of ERM (ezrin/radixin/moesin) proteins and furthermore triggering the recruitment of spleen tyrosine kinase (Syk) are very important in the process of tumor cell adhesion, migration and proliferation. At first, it was found that CD44/FERM structure was stable by observing CD44/FERM complex conformation and analyzing the interaction of interface residues both in static crystal structure and in equilibrium process. Meanwhile, unconventional immunoreceptor tyrosine-based activation motif (ITAM-like), and phosphorylation sites Y191 and Y205 were buried in FERM domain, which would hinder the phosphorylation of ERM proteins, the recruitment of Syk and subsequent signal transduction. Then, steered molecular dynamics simulation was applied to simulate the interaction between CD44 and FERM domain in the mechanical environment. The results showed that mechanical signal could induce the exposure of the ITAM-like motif and phosphorylation site Y205 by tracking and analyzing CD44/FERM complex conformational changes and the solvent-accessible surface area. This study revealed how the force regulates the activation of downstream signal through CD44 intracellular domain for the first time, and would be useful for further understanding the adhesion and migration pathway of cancer cells and the design of antitumor drugs.
Objective To investigate the changes of autophagy after spinal cord injury (SCI) in rats and its relationship with multisite phosphorylation of B-cell lymphoma-2 (Bcl-2) protein. Methods Forty male Sprague-Dawley rats aged 8 weeks were used to prepare SCI models by modified Allen method, and the SCI model were prepared successfully in 36 rats. The 36 SCI models were randomly divided into SCI group, autophagy inhibitor group, and autophagy promoter group, with 12 rats in each group. Another 12 rats were selected as sham operation group with only laminectomy and no spinal cord injury. At the end of modeling, the autophagy inhibitor group and the autophagy promoter group were intrathecally injected with 20 μL of 600 nmol/L 3-methyladenine and 25 nmol/L rapamycin, respectively, once a day for 4 weeks. The sham operation group and the SCI group were injected with only 20 μL of normal saline at the same time point. The motor function of rat in each group was evaluated by the Basso-Beattie-Bresnahan (BBB) score at 1 day and 1, 2, 4 weeks after modeling. The rats in each group were sacrificed at 24 hours after the last injection and the spinal cord tissues were taken. ELISA assay was used to detect the levels of inflammatory factors in spinal cord tissues, including myeloperoxidase (MPO), tumor necrosis factor α (TNF-α), and interleukin 1β (IL-1β); the morphological changes of spinal cord were observed by HE staining; the autophagy of mitochondria in spinal cord tissues was observed by transmission electron microscopy; the expressions of Beclin1 and microtubule-associated protein light chain 3 (LC3) were detected by immunofluorescence staining; neuronal apoptosis in spinal cord tissues were observed by TUNEL staining; LC3/TUNEL positive cells were calculated by immunofluorescence double staining; the expressions of Bcl-2 associated X protein (Bax), Bcl-2, p-Bcl-2 (Ser87), and p-Bcl-2 (Ser70) were detected by Western blot. Results Compared with sham operation group, BBB score of SCI group decreased at each time point, while the levels of MPO, TNF-α, and IL-1β increased; peripheral space of nerve cells enlarged, cells swelled, vacuoles appeared, and autophagic bodies appeared in mitochondria; the positive rates of Beclin1 and LC3 proteins, and apoptotic rate of neurons significantly increased; the LC3/TUNEL positive cells significantly increased; the expressions of Bax, p-Bcl-2 (Ser87), and p-Bcl-2 (Ser70) proteins increased, while the expression of Bcl-2 protein decreased; all showing significant differences (P<0.05). Compared with SCI group, BBB score in autophagy inhibitor group decreased at each time point, while the levels of MPO, TNF-α, and IL-1β increased; a few autophagic vesicles appeared in mitochondria; the positive rates of Beclin1 and LC3 proteins decreased and the apoptotic rate of neurons increased significantly; the LC3 positive cells decreased and the TUNEL positive cells increased; the expressions of Bax, p-Bcl-2 (Ser87), and p-Bcl-2 (Ser70) proteins increased, while the expression of Bcl-2 protein decreased. The results of autophagy promoter group were opposite to those of autophagy inhibitor group; all showing significant differences between groups (P<0.05). Conclusion Induction of autophagy after SCI in rats can reduce neuronal apoptosis and protect spinal cord function, which may be related to the inhibition of Bcl-2 protein multisite phosphorylation.