PICK1 (protein interacting with C kinase 1) contains a PDZ (PSD-95/Dlg/ZO1) domain and a BAR (Bin/amphiphysin/Rvs) domain. Via the PDZ domain, PICK1 interacts directly with more than 40 proteins. Among these interacting proteins, some are important for physiological and pathophysiological processes of central nervous system. In this review, recent findings about how PICK1 is associated with central nervous system diseases are summarize.
Animals ; Carrier Proteins ; chemistry ; metabolism ; physiology ; Epilepsy ; metabolism ; Humans ; Nuclear Proteins ; chemistry ; metabolism ; physiology ; Schizophrenia ; metabolism ; Stroke ; metabolism

This article is to summarize the molecular and functional analysis of the gene "suppression of tumorigenicity 13" (ST13). ST13 is in fact the gene encoding Hsp70 interacting protein (Hip), a co-factor (co-chaperone) of the 70-kDa heat shock proteins (Hsc/Hsp70). By collaborating with other positive co-factors such as Hsp40 and the Hsp70-Hsp90 organizing protein (Hop), or competing with negative co-factors such as Bcl2-associated athanogen 1 (Bag1), Hip facilitates may facilitate the chaperone function of Hsc/Hsp70 in protein folding and repair, and in controlling the activity of regulatory proteins such as steroid receptors and regulators of proliferation or apoptosis. Although the nomenclature of ST13 implies a role in the suppression of tumorigenicity (ST), to date available experimental data are not sufficient to support its role in cancer development, except for the possible down-regulation of ST13 in gastric and colorectal cancers. Further investigation of this gene at the physiological level would benefit our understanding of diseases such as endocrinological disorders, cancer, and neurodegeneration commonly associated with protein misfolding.
Adenosine Triphosphate ; metabolism ; Animals ; Carrier Proteins ; chemistry ; genetics ; physiology ; Cloning, Molecular ; HSP70 Heat-Shock Proteins ; metabolism ; Humans ; Protein Folding ; Tumor Suppressor Proteins ; chemistry ; genetics ; physiology

OBJECTIVESTo detect the cholesterol ester transfer protein (CETP) levels in semen of infertile patients and evaluate the correlation between CETP in semial plasma and infertility.

METHODSOne hundred and sixty-three infertile patients and fifteen fertile males were selected randomly. The routine examination of ejaculates was fulfilled by computer aided semen analysis (CASA). The CETP levels in all seminal plasma samples and fifty-five serum samples were detected by ELISA method.

RESULTSThe CETP levels in infertile patients and fertile males were (2.21 +/- 1.23) microgram/L and (1.40 +/- 0.45) microgram/L, respectively. There were no significant differences between the two groups(P > 0.05). And there were no significant differences of CETP levels in seminal plasma among groups of azoospermia(n = 29), oligoasthenozoospermia (n = 58), oligospermia(n = 15), asthenozoospermia(n = 44) and normozoospermia(n = 17) in the infertile patients(P > 0.05). The CETP in seminal plasma and serum were detected in 55 infertile patients, and there was no correlation between CETP levels in seminal plasma and serum using Spearman analysis(r = 0.009, P > 0.05). The mean CETP level in seminal plasma was almost 1/1,000 of that in serum.

CONCLUSIONSThe CETP level in seminal plasma is extremely low and has no relation with the changes of sperm density or motility. It may ensure the integrity of sperm membrane before the sperm enters into female genital tract.

Adult ; Carrier Proteins ; analysis ; blood ; Cholesterol Ester Transfer Proteins ; Glycoproteins ; Humans ; Infertility, Male ; metabolism ; Male ; Middle Aged ; Semen ; chemistry

OBJECTIVETo investigate the role of 83 site in interaction of GluR2 C-terminal and PICK1 PDZ domain.

METHODSDocking structure of PICK1 PDZ domain with GluR2 C terminal PDZ binding motif was built with computer software. After K83 site was substituted by other amino acid, the structure and binding energy were recalculated; meanwhile, site specific mutants were constructed using wild type full length cDNA as template. Mutants were co-transfected with GluR2 into HEK293T cells. After staining, the distribution of PICK1 and GluR2 were observed under confocal microscope.

RESULTSWild type PICK1 and GluR2 formed many co-clusters in HEK293T cells as reported by other research groups; but different K83 mutant had different distribution in HEK293T cells.

CONCLUSIONThe K83 site in PDZ domain of PICK1 is important for the interaction between PICK1 and GluR2. Altering lysine will probably change the hydrophobic interactions, the hydrogen bonds or the electrostatic interactions formed between PICK1 PDZ domain and GluR2 C terminal; accordingly, that will change the binding capacity between PICK1 and GluR2 in varying degrees.

Binding Sites ; Carrier Proteins ; chemistry ; metabolism ; Computer Simulation ; HEK293 Cells ; Humans ; Nuclear Proteins ; chemistry ; metabolism ; PDZ Domains ; Protein Binding ; Receptors, AMPA ; metabolism

Programmed necrosis, also known as necroptosis, has recently drawn great attention. As an important cellular regulation mechanism, knowledge of its signaling components is expanding. Necroptosisis demonstrated to be regulated by the RIP1 and RIP3 kinases, and its pathophysiological importance has been confirmed in a number of disease models. Here we review the new members of this necroptosis pathway, MLKL, PGAM5, Drp1 and DAI, and discuss some of their possible applications according to recent findings.
Animals ; Carrier Proteins ; metabolism ; DNA-Binding Proteins ; metabolism ; GTP Phosphohydrolases ; metabolism ; Humans ; Microtubule-Associated Proteins ; metabolism ; Mitochondrial Proteins ; metabolism ; Necrosis ; Phosphoprotein Phosphatases ; Protein Kinases ; chemistry ; metabolism ; Receptor-Interacting Protein Serine-Threonine Kinases ; metabolism ; Signal Transduction ; Tumor Necrosis Factors ; metabolism

SAG (Sensitive to Apoptosis Gene), also known as RBX2 (RING box protein 2), ROC2 (Regulator of Cullins 2), or RNF7 (RING Finger Protein 7), was originally cloned in our laboratory as a redox inducible antioxidant protein and later characterized as the second member of the RBX/ROC RING component of the SCF (SKP1-CUL-F-box Proteins) E3 ubiquitin ligase. When acting alone, SAG scavenges oxygen radicals by forming inter- and intra-molecular disulfide bonds, whereas by forming a complex with other components of the SCF E3 ligase, SAG promotes ubiquitination and degradation of a number of protein substrates, including c-JUN, DEPTOR, HIF-1α, IκBα, NF1, NOXA, p27, and procaspase-3, thus regulating various signaling pathways and biological processes. Specifically, SAG protects cells from apoptosis, confers radioresistance, and plays an essential and non-redundant role in mouse embryogenesis and vasculogenesis. Furthermore, stress-inducible SAG is overexpressed in a number of human cancers and SAG overexpression correlates with poor patient prognosis. Finally, SAG transgenic expression in epidermis causes an early stage inhibition, but later stage promotion, of skin tumorigenesis triggered by DMBA/TPA. Given its major role in promoting targeted degradation of tumor suppressive proteins, leading to apoptosis suppression and accelerated tumorigenesis, SAG E3 ligase appears to be an attractive anticancer target.
Animals ; Antioxidants ; metabolism ; Apoptosis ; Carrier Proteins ; chemistry ; genetics ; metabolism ; Cell Transformation, Neoplastic ; Humans ; RING Finger Domains ; Substrate Specificity ; Ubiquitin-Protein Ligases ; chemistry ; metabolism ; Ubiquitination

Autophagy is an evolutionarily conserved cellular process which degrades intracellular contents. The Atg17-Atg31-Atg29 complex plays a key role in autophagy induction by various stimuli. In yeast, autophagy occurs with autophagosome formation at a special site near the vacuole named the pre-autophagosomal structure (PAS). The Atg17-Atg31-Atg29 complex forms a scaffold for PAS organization, and recruits other autophagy-related (Atg) proteins to the PAS. Here, we show that Atg31 is a phosphorylated protein. The phosphorylation sites on Atg31 were identified by mass spectrometry. Analysis of mutants in which the phosphorylated amino acids were replaced by alanine, either individually or in various combinations, identified S174 as the functional phosphorylation site. An S174A mutant showed a similar degree of autophagy impairment as an Atg31 deletion mutant. S174 phosphorylation is required for autophagy induced by various autophagy stimuli such as nitrogen starvation and rapamycin treatment. Mass spectrometry analysis showed that S174 is phosphorylated constitutively, and expression of a phosphorylation-mimic mutant (S174D) in the Atg31 deletion strain restores autophagy. In the S174A mutant, Atg9-positive vesicles accumulate at the PAS. Thus, S174 phosphorylation is required for formation of autophagosomes, possibly by facilitating the recycling of Atg9 from the PAS. Our data demonstrate the role of phosphorylation of Atg31 in autophagy.
Alanine ; chemistry ; metabolism ; Amino Acid Motifs ; Aspartic Acid ; chemistry ; metabolism ; Autophagy ; genetics ; Autophagy-Related Proteins ; Carrier Proteins ; chemistry ; metabolism ; Gene Expression Regulation, Fungal ; Membrane Proteins ; chemistry ; metabolism ; Models, Molecular ; Molecular Sequence Data ; Nitrogen ; deficiency ; Phagosomes ; chemistry ; drug effects ; metabolism ; Phosphorylation ; Protein Transport ; Saccharomyces cerevisiae ; drug effects ; genetics ; metabolism ; Saccharomyces cerevisiae Proteins ; chemistry ; genetics ; metabolism ; Serine ; chemistry ; metabolism ; Signal Transduction ; Sirolimus ; pharmacology

In recent years, human cancer genome projects provide unprecedented opportunities for the discovery of cancer genes and signaling pathways that contribute to tumor development. While numerous gene mutations can be identified from each cancer genome, what these mutations mean for cancer is a challenging question to address, especially for those from less understood putative new cancer genes. As a powerful approach, in silico bioinformatics analysis could efficiently sort out mutations that are predicted to damage gene function. Such an analysis of human large tumor suppressor genes, LATS1 and LATS2, has been carried out and the results support a role of hLATS1//2 as negative growth regulators and tumor suppressors.
Adaptor Proteins, Signal Transducing ; chemistry ; metabolism ; Animals ; Carrier Proteins ; chemistry ; metabolism ; Computational Biology ; Genes, Neoplasm ; Humans ; LIM Domain Proteins ; chemistry ; metabolism ; Mice ; Mutation ; Neoplasms ; genetics ; pathology ; Phosphoproteins ; chemistry ; metabolism ; Phosphorylation ; Protein Binding ; Protein Structure, Tertiary ; Protein-Serine-Threonine Kinases ; chemistry ; genetics ; metabolism ; Transferases (Other Substituted Phosphate Groups) ; chemistry ; metabolism ; Tumor Suppressor Proteins ; chemistry ; genetics ; metabolism

Bone sialoprotein-binding protein (Bbp), a MSCRAMMs (Microbial Surface Components Recognizing Adhesive Matrix Molecules) family protein expressed on the surface of Staphylococcus aureus (S. aureus), mediates adherence to fibrinogen α (Fg α), a component in the extracellular matrix of the host cell and is important for infection and pathogenesis. In this study, we solved the crystal structures of apo-Bbp(273-598) and Bbp(273-598)-Fg α(561-575) complex at a resolution of 2.03 Å and 1.45 Å, respectively. Apo-Bbp(273-598) contained the ligand binding region N2 and N3 domains, both of which followed a DE variant IgG fold characterized by an additional D1 strand in N2 domain and D1' and D2' strands in N3 domain. The peptide mapped to the Fg α(561-575) bond to Bbp(273-598) on the open groove between the N2 and N3 domains. Strikingly, the disordered C-terminus in the apo-form reorganized into a highly-ordered loop and a β-strand G'' covering the ligand upon ligand binding. Bbp(Ala298-Gly301) in the N2 domain of the Bbp(273-598)-Fg α(561-575) complex, which is a loop in the apo-form, formed a short α-helix to interact tightly with the peptide. In addition, Bbp(Ser547-Gln561) in the N3 domain moved toward the binding groove to make contact directly with the peptide, while Bbp(Asp338-Gly355) and Bbp(Thr365-Tyr387) in N2 domain shifted their configurations to stabilize the reorganized C-terminus mainly through strong hydrogen bonds. Altogether, our results revealed the molecular basis for Bbp-ligand interaction and advanced our understanding of S. aureus infection process.
Bacterial Proteins ; chemistry ; genetics ; metabolism ; Carrier Proteins ; chemistry ; genetics ; metabolism ; Crystallography, X-Ray ; Fibrinogen ; metabolism ; Ligands ; Models, Molecular ; Mutation ; Peptide Fragments ; chemistry ; metabolism ; Protein Binding ; Protein Structure, Tertiary ; Staphylococcus aureus

OBJECTIVETo clarify the role of midkine (MK) in vulvar carcinogenesis though examination of its expression in vulvar lesions including vulvar condyloma acuminata (VCA), vulvar intraepithelial neoplasia (VIN) and vulvar squamous cell carcinomas (VSCC), and to analyze the relationship between MK expression and human papilloma virus (HPV) infection.

METHODSThirty VSCC, 15 VIN and 10 VCA patients were studied by streptavidin-biotin-immunoperoxidase method. MK expression was compared with clinicopathologic features of vulvar tumors.

RESULTSMK was expressed in 26 of 30 VSCC (87%), 3 of 5 VIN III and all VCA samples, whereas no MK expression was detected in the VIN I-II samples or in normal epithelium. The difference of MK expression between VIN III and VSCC was statistically significant (P < 0.05). MK was more intensely expressed in differentiated-type (well differentiated and moderately differentiated) VSCC than in undifferentiated-type (poorly differentiated) VSCC. There was no statistically significant correlation between MK expression and clinical stage, lymph node metastasis and HPV infection in VSCC. MK expression were observed in all HPV-positive specimens including 2 VSCC, 1 VIN III and all VCA.

CONCLUSIONSMK gene expression may be a late event in vulvar squamous cell malignant transformation, and may be associated with vulvar tumor cell differentiation. HPV-positive vulvar tumors expressed MK protein.

Carcinoma, Squamous Cell ; chemistry ; virology ; Carrier Proteins ; biosynthesis ; Condylomata Acuminata ; metabolism ; virology ; Cytokines ; Female ; Humans ; Papillomaviridae ; chemistry ; Papillomavirus Infections ; metabolism ; Precancerous Conditions ; chemistry ; virology ; Tumor Virus Infections ; metabolism ; Vulvar Diseases ; metabolism ; virology ; Vulvar Neoplasms ; chemistry ; virology