BACKGROUND: Golgi protein 73 (GP73) is a promising bio- marker of hepatocellular carcinoma (HCC). It decreases after surgical resection, and resumes upon recurrence, indicating a potential indicator for the effec...BACKGROUND: Golgi protein 73 (GP73) is a promising bio- marker of hepatocellular carcinoma (HCC). It decreases after surgical resection, and resumes upon recurrence, indicating a potential indicator for the effectiveness of the treatment. But changes of GP73 after transcatheter arterial chemoemboliza- tion (TACE) have not been reported so far. This study was to investigate the dynamic changes of GP73 in HCC patients af- ter TACE treatment, and the possible underlying mechanisms in the cell cultures. METHODS: Blood samples were collected from 72 HCC pa- tients, before TACE, at day I and day 30 after TACE. GP73 lev- els were measured by Western blotting. The dynamic changes of GP73 were analyzed and compared with image changes and clinical data. The effects of chemotherapeutic agents (5-FU and pirarubicin) on GP73 expression were tested in three HCC cell lines (HepG2, HCCLM3 and MHCC97H). RESULTS: The GP73 level was significantly elevated at day 1 and day 30 after TACE in HCC patients compared with that before the procedure (P〈0.05). There was no statistical differ- ence between the two time points after TACE, nor correlationbetween GP73 levels and dinicopathological features, tumor metastasis, and patient survival. Pirarubicin, not 5-FU, signifi- cantly increased GP73 expression in three cell lines. CONCLUSIONS: Unlike surgical resection which decreases the GP73 level, TACE significantly increased GP73 expression in patients with HCC. No correlations were observed among GP73 levels, tumor characteristics and prognosis of patients with HCC.展开更多
BACKGROUND Microwave ablation(MWA)is an effective treatment option for patients with primary liver cancer.However,it has been reported that the MWA procedure induces a hepatic inflammatory response and injury,which ma...BACKGROUND Microwave ablation(MWA)is an effective treatment option for patients with primary liver cancer.However,it has been reported that the MWA procedure induces a hepatic inflammatory response and injury,which may negatively affect the efficacy of MWA.As such,the discovery of reliable markers to monitor the patient’s response to MWA is needed.Golgi protein 73(GP73)has been shown to be associated with chronic liver disease.To date,the potential value of serum GP73 in the dynamic monitoring during MWA of liver cancer remains unclear.AIM To examine the effects of MWA on the serum levels of GP73 in patients with primary liver cancer.METHODS A total of 150 primary liver cancer patients with a single small lesion(≤3 cm in diameter)were retrospectively enrolled spanning the period between January 2016 and October 2018.All of the patients received MWA for the treatment of primary liver cancer.Serum GP73,alpha-fetoprotein(AFP),and widely used liver biochemical indicators[serum albumin,total bilirubin(TBIL),alanine aminotransferase(ALT),and aspartate aminotransferase(AST)]were compared before MWA and at different time points,including 1,2,and 4 wk following the ablation procedure.RESULTS Complete tumor ablation was achieved in 95.33%of the patients at 1 mo after MWA.The 1-,2-,and 3-year disease-free survival rates were 74.67%,59.33%,and 54.00%,respectively.The serum AFP levels were significantly decreased at 1,2,and 4 wk after MWA;they returned to the normal range at 12 wk after MWA;and they remained stable thereafter during follow-up in those cases without recurrence.In contrast,the serum GP73 levels were significantly increased at 1 and 2 wk after MWA.The serum GP73 levels reached the peak at 2 wk after MWA,started to decline after hepatoprotective treatment with glycyrrhizin and reduced glutathione,and returned to the pretreatment levels at 12 and 24 wk after MWA.Notably,the changes of serum GP73 in response to MWA were similar to those of TBIL,ALT,and AST.CONCLUSION Serum GP73 is markedly increased in response to MWA of liver cancer.Thus,serum GP73 holds potential as a marker to monitor MWA-induced inflammatory liver injury in need of amelioration.展开更多
Objective: The aim of the present study was to further evaluate the clinical value of single or joint of golgi protein 73 (GP73) and alphafetoprotein (AFP) in diagnosis of hepatocellular (HCC). Methods: One hundred an...Objective: The aim of the present study was to further evaluate the clinical value of single or joint of golgi protein 73 (GP73) and alphafetoprotein (AFP) in diagnosis of hepatocellular (HCC). Methods: One hundred and eighteen, 94 and 47 serum samples from the patients with HCC, chronic liver disease (CLD) and liver cirrhosis (LC) were collected, respectively. Serum levels of AFP and GP73 were assayed with commercial kit according to the manufacturer's instructions. Results: Patients with HCC had higher serum concentration of AFP than that of the patients with CLD (P < 0.01), but was similar to that of the patients with LC. Serum GP73 levels in the patients with CLD or LC were significantly lower than that in the patients from HCC group (P < 0.01). Among 118 HCC patients, the positive rate of GP73 and AFP was 80.5% and 48.3%, respectively (P < 0.001). The ROC curve analysis showed that the AUC value of GP73 was higher than that of serum AFP. Moreover, the sensitivity and the accuracy of GP73 were 77.1% and 82.6%, respectively, which were greater more than that of AFP at 90% specificity (28.8% and 59.8%, respectively). The AUC, the sensitivity and the accuracy of GP73 in combination of AFP (AFP/GP73) were 0.855, 78.0% and 83.0%, respectively, which were similar to that of GP73 alone but were much higher than that of the single marker AFP. Conclusion: For HCC diagnosing, GP73 was more sensitive and specific than AFP. The diagnostic value of AFP/GP73 was similar to GP73 but was much higher than AFP.展开更多
Aim: We measured Golgi protein73 (GP73), alpha-fetoprotein (AFP), and vascular endothelial growth factor (VEGF) expression in primary hepatic cancer (PHC) and assessed their clinical significance. Methods: Forty-five ...Aim: We measured Golgi protein73 (GP73), alpha-fetoprotein (AFP), and vascular endothelial growth factor (VEGF) expression in primary hepatic cancer (PHC) and assessed their clinical significance. Methods: Forty-five PHC and tumor-adjacent specimens and 14 normal liver specimens were examined. GP73, AFP, and VEGF expression was measured via immunohistochemistry and a correlation of protein expression with clinical pathology of PHC was suggested. Results: GP73, AFP, and VEGF expression was significantly higher in PHC and tumor-adjacent tissue compared to tumor-adjacent tissue (0.143 ± 0.018 vs. 0.124 ± 0.027, 0.116 ± 0.026 vs. 0.098 ± 0.014, and 0.126 ± 0.027 vs. 0.092 ± 0.016, respectively;all p 0.088 ± 0.029, 0.098 ± 0.014 vs. 0.073 ± 0.011, and 0.092 ± 0.016 vs. 0.076 ± 0.018, respectively;all p < 0.05), respectively. GP73 expression was positively correlated with pathological grade and cirrhosis, but not with tumor size, nodules, clinical stage and serum AFP. VEGF expression was positively correlated with tumor size, nodules, portal vein tumor thrombus, and clinical stage, but not with the degree of tumor differentiation and serum AFP. Expression of GP73 and VEGF was greater than that of AFP in PHC (both p < 0.05). Conclusion: GP73 is highly expressed in PHC and may be a diagnostic marker. Combined detection of GP73, AFP, and VEGF is helpful for diagnosis of PHC.展开更多
Hepatocellular carcinoma(HCC)is one of the most common malignant tumors with a low survival rate.The identification of mechanisms underlying the development of HCC helps uncover cellular and mo-lecular targets for the...Hepatocellular carcinoma(HCC)is one of the most common malignant tumors with a low survival rate.The identification of mechanisms underlying the development of HCC helps uncover cellular and mo-lecular targets for the diagnosis,prevention,and treatment of HCC.Golgi protein 73(GP73)level is up-regulated in HCC patients and potentially can be a therapeutic target.Despite many studies devoted to GP73 as a marker for HCC early diagnosis,there is little discussion about the function of GP73 in HCC tumorigenesis.Given the poor response to currently available HCC therapies,a better understanding of the role of GP73 in HCC may provide a new therapeutic target for HCC.The current paper summarizes the role of GP73 as a diagnostic marker as well as its roles in liver carcinogenesis.Its roles in other types of cancer are also discussed.展开更多
Background and Aims:As a hepatocellular carcinoma biomarker,serum Golgi protein 73(GP73)is reportedly related to inflammation.Acute-on-chronic liver failure(ACLF)is characterized by severe systemic inflammation.In thi...Background and Aims:As a hepatocellular carcinoma biomarker,serum Golgi protein 73(GP73)is reportedly related to inflammation.Acute-on-chronic liver failure(ACLF)is characterized by severe systemic inflammation.In this study,we aimed to explore the association between the GP73 level and short-term mortality in patients with alcohol-associated liver disease-related ACLF(ALD-ACLF).Methods:This retrospective cohort study involved 126 Chinese adults with ALD-ACLF.Baseline serum GP73 level was measured using enzymelinked immunosorbent assay.Patients were followed-up for 90 d and outcomes were assessed.Data were analyzed using multivariate Cox regression and piecewise linear regression analyses.The predictive value of GP73 and classic models for the short-term prognosis of participants were evaluated and compared using receiver operating characteristic curves.Results:The serum GP73 level was independently associated with an increased mortality risk in patients with ALD-ACLF.Compared with the lowest tertile,the highest serum GP73 level predisposed patients with ALD-ACLF to a higher mortality risk in the fully adjusted model[at 28 days:hazard ratio(HR):4.29(0.99–18.54),p=0.0511;at 90 days:HR:3.52(1.15–10.79),p=0.0276].Further analysis revealed a positive linear association.GP73 significantly improved the accuracy of the Child-Turcotte-Pugh score,model for end-stage liver disease score,and model for end-stage liver diseasesodium score in predicting short-time prognosis of patients with ALD-ACLF.Conclusions:The serum GP73 level is a significant predictor of the subsequent risk of death in patients with ALD-ACLF.GP73 improved the predictive value of classic prognostic scores.展开更多
AIM: To investigate the effect of Golgi phosphorylation protein 3(GOLPH3) expression on cell apoptosis, angiogenesis and prognosis in colorectal cancer(CRC). METHODS: The expression of GOLPH3 in CRC tissues and normal...AIM: To investigate the effect of Golgi phosphorylation protein 3(GOLPH3) expression on cell apoptosis, angiogenesis and prognosis in colorectal cancer(CRC). METHODS: The expression of GOLPH3 in CRC tissues and normal colorectal mucosae was determined by immunohistochemistry in 62 patients. In addition, immunohistochemistry was also carried out to detect the expression of vascular endothelial growth factor(VEGF), CD34 and microvessel density(MVD). Terminal deoxynucleotidyl transferase-mediated d UTP-biotin nick end labeling assay was used to determine the apoptotic index(AI). The Kaplan-Meier method was used to analyze the relationship between GOLPH3 expression and survival in another 123 CRC cases.RESULTS: Compared with normal colorectal mucosae, a notably higher level of GOLPH3 protein expression was identified in CRC tissues(53.2% vs 24.2%, P < 0.05). Positive GOLPH3 expression was significantly associated with tumor invasion depth, TNM stage, and lymph node metastasis(P = 0.001; P = 0.020; P = 0.020; P < 0.05, respectively), but not with tumor length, tumor site, and age(P = 0.363; P = 0.819; P = 0.599; P > 0.05, respectively). VEGF expression and MVD in GOLPH3-positive CRC was significantly higher than in GOLPH3-negative CRC(VEGF: 69.7% vs 31.0%; MVD: 21.45 ± 9.39 vs 14.24 ± 8.97; P < 0.05).GOLPH3 expression was negatively correlated with AI in CRC as shown by Spearman correlation analysis(r =-0.320, P < 0.05). The 5-year survival rate in GOLPH3-negative CRC(69.4%) was significantly higher than in GOLPH3-positive CRC(48.6%)(log-rank test, P < 0.05).CONCLUSION: High expression of GOLPH3 is found in CRC tissues. GOLPH3 expression may be a novel prognostic marker for CRC patients.展开更多
Newly synthesized membrane and secretory proteins in cells undergo folding in the endoplasmic reticulum with the introduction of disulfide bonds and acquire the correct three-dimensional structure. Disulfide bonds are...Newly synthesized membrane and secretory proteins in cells undergo folding in the endoplasmic reticulum with the introduction of disulfide bonds and acquire the correct three-dimensional structure. Disulfide bonds are especially important for protein folding. It has been thought that formation of protein disulfide bonds in eukaryotes is mainly carried out by an enzyme called protein disulfide isomerase. Proteins, bearing the C-terminus of amino acids sequences with His-Asp-Glu-Leu (HDEL) sequence in yeast, in the endoplasmic reticulum (ER), which is a eukaryotic cellular organelle involved in protein synthesis, processing, and transport, have been considered to recycle between ER and Golgi apparatus. The proposal for this recycling model derives from the study of an HDEL-tagged fusion protein. Here, the localization and oligosaccharide modification of protein disulfide isomerase were investigated in yeast, and showed the first direct evidence that this intrinsic ER protein transports from ER to Golgi. Results suggest that this native protein is also accessible to post-ER enzymes, and yet accumulates in the ER.展开更多
基金supported by grants from the National Key Technology Research and Development Program of China 2012(BAI06B01)the National Natural Science Foundation of China(81201566)+1 种基金the Specialized Research Fund for the Doctoral Program of Higher Education(20121106110002)Wu Jieping Medical Foundation(LDWMF-SY-2011B002)
文摘BACKGROUND: Golgi protein 73 (GP73) is a promising bio- marker of hepatocellular carcinoma (HCC). It decreases after surgical resection, and resumes upon recurrence, indicating a potential indicator for the effectiveness of the treatment. But changes of GP73 after transcatheter arterial chemoemboliza- tion (TACE) have not been reported so far. This study was to investigate the dynamic changes of GP73 in HCC patients af- ter TACE treatment, and the possible underlying mechanisms in the cell cultures. METHODS: Blood samples were collected from 72 HCC pa- tients, before TACE, at day I and day 30 after TACE. GP73 lev- els were measured by Western blotting. The dynamic changes of GP73 were analyzed and compared with image changes and clinical data. The effects of chemotherapeutic agents (5-FU and pirarubicin) on GP73 expression were tested in three HCC cell lines (HepG2, HCCLM3 and MHCC97H). RESULTS: The GP73 level was significantly elevated at day 1 and day 30 after TACE in HCC patients compared with that before the procedure (P〈0.05). There was no statistical differ- ence between the two time points after TACE, nor correlationbetween GP73 levels and dinicopathological features, tumor metastasis, and patient survival. Pirarubicin, not 5-FU, signifi- cantly increased GP73 expression in three cell lines. CONCLUSIONS: Unlike surgical resection which decreases the GP73 level, TACE significantly increased GP73 expression in patients with HCC. No correlations were observed among GP73 levels, tumor characteristics and prognosis of patients with HCC.
基金Supported by the Military Medical Science and Technology Committee of China,No.14MS095the Quanzhou Science and Technology Planning Project,No.2017Z018.
文摘BACKGROUND Microwave ablation(MWA)is an effective treatment option for patients with primary liver cancer.However,it has been reported that the MWA procedure induces a hepatic inflammatory response and injury,which may negatively affect the efficacy of MWA.As such,the discovery of reliable markers to monitor the patient’s response to MWA is needed.Golgi protein 73(GP73)has been shown to be associated with chronic liver disease.To date,the potential value of serum GP73 in the dynamic monitoring during MWA of liver cancer remains unclear.AIM To examine the effects of MWA on the serum levels of GP73 in patients with primary liver cancer.METHODS A total of 150 primary liver cancer patients with a single small lesion(≤3 cm in diameter)were retrospectively enrolled spanning the period between January 2016 and October 2018.All of the patients received MWA for the treatment of primary liver cancer.Serum GP73,alpha-fetoprotein(AFP),and widely used liver biochemical indicators[serum albumin,total bilirubin(TBIL),alanine aminotransferase(ALT),and aspartate aminotransferase(AST)]were compared before MWA and at different time points,including 1,2,and 4 wk following the ablation procedure.RESULTS Complete tumor ablation was achieved in 95.33%of the patients at 1 mo after MWA.The 1-,2-,and 3-year disease-free survival rates were 74.67%,59.33%,and 54.00%,respectively.The serum AFP levels were significantly decreased at 1,2,and 4 wk after MWA;they returned to the normal range at 12 wk after MWA;and they remained stable thereafter during follow-up in those cases without recurrence.In contrast,the serum GP73 levels were significantly increased at 1 and 2 wk after MWA.The serum GP73 levels reached the peak at 2 wk after MWA,started to decline after hepatoprotective treatment with glycyrrhizin and reduced glutathione,and returned to the pretreatment levels at 12 and 24 wk after MWA.Notably,the changes of serum GP73 in response to MWA were similar to those of TBIL,ALT,and AST.CONCLUSION Serum GP73 is markedly increased in response to MWA of liver cancer.Thus,serum GP73 holds potential as a marker to monitor MWA-induced inflammatory liver injury in need of amelioration.
基金Supported by a grant from the International Collaboration Program from Nanjing Science and Technology Bureau (No. 201001139)
文摘Objective: The aim of the present study was to further evaluate the clinical value of single or joint of golgi protein 73 (GP73) and alphafetoprotein (AFP) in diagnosis of hepatocellular (HCC). Methods: One hundred and eighteen, 94 and 47 serum samples from the patients with HCC, chronic liver disease (CLD) and liver cirrhosis (LC) were collected, respectively. Serum levels of AFP and GP73 were assayed with commercial kit according to the manufacturer's instructions. Results: Patients with HCC had higher serum concentration of AFP than that of the patients with CLD (P < 0.01), but was similar to that of the patients with LC. Serum GP73 levels in the patients with CLD or LC were significantly lower than that in the patients from HCC group (P < 0.01). Among 118 HCC patients, the positive rate of GP73 and AFP was 80.5% and 48.3%, respectively (P < 0.001). The ROC curve analysis showed that the AUC value of GP73 was higher than that of serum AFP. Moreover, the sensitivity and the accuracy of GP73 were 77.1% and 82.6%, respectively, which were greater more than that of AFP at 90% specificity (28.8% and 59.8%, respectively). The AUC, the sensitivity and the accuracy of GP73 in combination of AFP (AFP/GP73) were 0.855, 78.0% and 83.0%, respectively, which were similar to that of GP73 alone but were much higher than that of the single marker AFP. Conclusion: For HCC diagnosing, GP73 was more sensitive and specific than AFP. The diagnostic value of AFP/GP73 was similar to GP73 but was much higher than AFP.
文摘Aim: We measured Golgi protein73 (GP73), alpha-fetoprotein (AFP), and vascular endothelial growth factor (VEGF) expression in primary hepatic cancer (PHC) and assessed their clinical significance. Methods: Forty-five PHC and tumor-adjacent specimens and 14 normal liver specimens were examined. GP73, AFP, and VEGF expression was measured via immunohistochemistry and a correlation of protein expression with clinical pathology of PHC was suggested. Results: GP73, AFP, and VEGF expression was significantly higher in PHC and tumor-adjacent tissue compared to tumor-adjacent tissue (0.143 ± 0.018 vs. 0.124 ± 0.027, 0.116 ± 0.026 vs. 0.098 ± 0.014, and 0.126 ± 0.027 vs. 0.092 ± 0.016, respectively;all p 0.088 ± 0.029, 0.098 ± 0.014 vs. 0.073 ± 0.011, and 0.092 ± 0.016 vs. 0.076 ± 0.018, respectively;all p < 0.05), respectively. GP73 expression was positively correlated with pathological grade and cirrhosis, but not with tumor size, nodules, clinical stage and serum AFP. VEGF expression was positively correlated with tumor size, nodules, portal vein tumor thrombus, and clinical stage, but not with the degree of tumor differentiation and serum AFP. Expression of GP73 and VEGF was greater than that of AFP in PHC (both p < 0.05). Conclusion: GP73 is highly expressed in PHC and may be a diagnostic marker. Combined detection of GP73, AFP, and VEGF is helpful for diagnosis of PHC.
基金This study was supported bygrants funded by the USA National Institutes of Health(NIH)R01CA222490 to Y.-J.Y.Wanalong with grants from the National Natural Science Foundation of China Project number 81602456financial sup-port from the China Scholarship Council(CSC)to Y.Wang.
文摘Hepatocellular carcinoma(HCC)is one of the most common malignant tumors with a low survival rate.The identification of mechanisms underlying the development of HCC helps uncover cellular and mo-lecular targets for the diagnosis,prevention,and treatment of HCC.Golgi protein 73(GP73)level is up-regulated in HCC patients and potentially can be a therapeutic target.Despite many studies devoted to GP73 as a marker for HCC early diagnosis,there is little discussion about the function of GP73 in HCC tumorigenesis.Given the poor response to currently available HCC therapies,a better understanding of the role of GP73 in HCC may provide a new therapeutic target for HCC.The current paper summarizes the role of GP73 as a diagnostic marker as well as its roles in liver carcinogenesis.Its roles in other types of cancer are also discussed.
基金supported by a grant from the Capital’s Funds for Health Improvement and Research,China(NO.2020-1-5031).
文摘Background and Aims:As a hepatocellular carcinoma biomarker,serum Golgi protein 73(GP73)is reportedly related to inflammation.Acute-on-chronic liver failure(ACLF)is characterized by severe systemic inflammation.In this study,we aimed to explore the association between the GP73 level and short-term mortality in patients with alcohol-associated liver disease-related ACLF(ALD-ACLF).Methods:This retrospective cohort study involved 126 Chinese adults with ALD-ACLF.Baseline serum GP73 level was measured using enzymelinked immunosorbent assay.Patients were followed-up for 90 d and outcomes were assessed.Data were analyzed using multivariate Cox regression and piecewise linear regression analyses.The predictive value of GP73 and classic models for the short-term prognosis of participants were evaluated and compared using receiver operating characteristic curves.Results:The serum GP73 level was independently associated with an increased mortality risk in patients with ALD-ACLF.Compared with the lowest tertile,the highest serum GP73 level predisposed patients with ALD-ACLF to a higher mortality risk in the fully adjusted model[at 28 days:hazard ratio(HR):4.29(0.99–18.54),p=0.0511;at 90 days:HR:3.52(1.15–10.79),p=0.0276].Further analysis revealed a positive linear association.GP73 significantly improved the accuracy of the Child-Turcotte-Pugh score,model for end-stage liver disease score,and model for end-stage liver diseasesodium score in predicting short-time prognosis of patients with ALD-ACLF.Conclusions:The serum GP73 level is a significant predictor of the subsequent risk of death in patients with ALD-ACLF.GP73 improved the predictive value of classic prognostic scores.
基金Supported by The Scientific Research Fund from the Science and Technology Bureau of QuanzhouChinaNo.2010Z33
文摘AIM: To investigate the effect of Golgi phosphorylation protein 3(GOLPH3) expression on cell apoptosis, angiogenesis and prognosis in colorectal cancer(CRC). METHODS: The expression of GOLPH3 in CRC tissues and normal colorectal mucosae was determined by immunohistochemistry in 62 patients. In addition, immunohistochemistry was also carried out to detect the expression of vascular endothelial growth factor(VEGF), CD34 and microvessel density(MVD). Terminal deoxynucleotidyl transferase-mediated d UTP-biotin nick end labeling assay was used to determine the apoptotic index(AI). The Kaplan-Meier method was used to analyze the relationship between GOLPH3 expression and survival in another 123 CRC cases.RESULTS: Compared with normal colorectal mucosae, a notably higher level of GOLPH3 protein expression was identified in CRC tissues(53.2% vs 24.2%, P < 0.05). Positive GOLPH3 expression was significantly associated with tumor invasion depth, TNM stage, and lymph node metastasis(P = 0.001; P = 0.020; P = 0.020; P < 0.05, respectively), but not with tumor length, tumor site, and age(P = 0.363; P = 0.819; P = 0.599; P > 0.05, respectively). VEGF expression and MVD in GOLPH3-positive CRC was significantly higher than in GOLPH3-negative CRC(VEGF: 69.7% vs 31.0%; MVD: 21.45 ± 9.39 vs 14.24 ± 8.97; P < 0.05).GOLPH3 expression was negatively correlated with AI in CRC as shown by Spearman correlation analysis(r =-0.320, P < 0.05). The 5-year survival rate in GOLPH3-negative CRC(69.4%) was significantly higher than in GOLPH3-positive CRC(48.6%)(log-rank test, P < 0.05).CONCLUSION: High expression of GOLPH3 is found in CRC tissues. GOLPH3 expression may be a novel prognostic marker for CRC patients.
文摘Newly synthesized membrane and secretory proteins in cells undergo folding in the endoplasmic reticulum with the introduction of disulfide bonds and acquire the correct three-dimensional structure. Disulfide bonds are especially important for protein folding. It has been thought that formation of protein disulfide bonds in eukaryotes is mainly carried out by an enzyme called protein disulfide isomerase. Proteins, bearing the C-terminus of amino acids sequences with His-Asp-Glu-Leu (HDEL) sequence in yeast, in the endoplasmic reticulum (ER), which is a eukaryotic cellular organelle involved in protein synthesis, processing, and transport, have been considered to recycle between ER and Golgi apparatus. The proposal for this recycling model derives from the study of an HDEL-tagged fusion protein. Here, the localization and oligosaccharide modification of protein disulfide isomerase were investigated in yeast, and showed the first direct evidence that this intrinsic ER protein transports from ER to Golgi. Results suggest that this native protein is also accessible to post-ER enzymes, and yet accumulates in the ER.