Patient perceptions of symptoms and concerns during cancer chemotherapy: 'affects my family' is the most important

Background

Cancer chemotherapy is associated with a variety of side effects/adverse events. It is very important that patients adhere to the planned chemotherapy regimen, which necessitates a minimum of side effects and that these side effects be kept under control. We have investigated patients’ concerns and symptoms during chemotherapy with the aim to seek solutions that will improve patients’ quality of life during chemotherapy.

Methods

Forty-nine patients with malignant diseases on parenteral antineoplastic agents were sequentially enrolled in this study. These patients completed a questionnaire consisting of 42 items related to non-physical concerns and 52 items of physical symptoms related to chemotherapy. Each patient was also asked to select the three items among these 94 items which affected him/her the most.

Results

The median age of the cancer patients was 62 years and the male-to-female ratio was 18:31. Among the non-physical concerns, the most frequently chosen concern was ‘affects my family or partner,’ followed by anxiety related to treatment. Regarding the physical symptoms, the most frequent complaints were fatigue, alopecia and constipation, while the most troublesome symptoms were nausea, poor taste and paresthesia. Overall, the most frequently expressed concerns were ‘affects my family or partner’ and anxiety related to treatment. Male patients suffered most from fever, fatigue and nausea, and female patients complained more of poor taste and gastrointestinal problems.

Conclusion

Patient perceptions of adverse events associated with cancer chemotherapy apparently have changed from physical symptoms to non-physical concerns. In our patient cohort ‘affects my family or partner’ was the most important concern. One important point to note is that female patients often complained of poor taste because this meant they were unable to cook well.

Electronic supplementary material

The online version of this article (doi:10.1007/s10147-017-1117-y) contains supplementary material, which is available to authorized users.

The method of mouse embryoid body establishment affects structure and developmental gene expression

To investigate formation of the three primary germ layers in mouse embryoid bodies (EBs), we observed changes in structure and gene expression over a 7-day culture period. We compared these changes using two methods for EB formation: hanging drop (HD) and static suspension culture (SSC). Light microscopy showed that a stratified columnar epithelial layer developed on the surface of EBs formed using the HD method. From Day 3 in culture, ultrastructural changes occurred in the aligned cellular membranes. Condensation of actin filaments was followed by formation of complicated adherent junctions and dilatation of intercellular canaliculi containing well-developed microvilli. These changes were more marked in EBs formed by the HD method than the SSC method. On Day 5 of culture, Brachyury gene expression, a marker for mesoderm formation, was detected only with the HD method. Nestin, an ectoderm marker, and Foxa2, an endoderm marker, were expressed with both methods. These results suggest that in EBs formed with the HD method, actin formation and Brachyury gene expression mark the transition from two to three primary germ layers. Additionally, the HD method promotes more rapid and complete development of mouse EBs than does the SSC method. While the SSC method is simple and easy to use, it needs improvement to form more complete EBs.

The clinical significance of Cyclin B1 and Wee1 expression in non-small-cell lung cancer

BACKGROUND

Cyclin B1 has an important role in the G2-M phase transition of the cell cycle. Wee1 delays mitosis by suppressing the activity of the Cyclin B1/cdc2 complex. The objective of the present study was to elucidate the clinicopathological and prognostic significance of Cyclin B1 and Wee1 expression in non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

An immunohistochemical assessment of Cyclin B1 and Wee1 expression was performed in 79 patients with NSCLC.

RESULTS

The expression of Cyclin B1 was correlated with differentiation (P = 0.0423) and vascular invasion (P = 0.001). Patients with overexpression of Cyclin B1 had higher mean values for both the Ki-67 proliferative index (Ki-Index) (P <0.0001) and proliferating cell nuclear antigen labeling index (PCNA-LI) (P <0.0001), and a poorer prognosis (P = 0.0068). Patients lacking expression of Wee1 had a higher recurrence rate (P = 0.0084) and a poorer prognosis (P = 0.0457), and tended to have higher Ki-Index and PCNA-LI values. Multivariate analysis suggested that both Cyclin B1 (P = 0.0244) and Wee1 (P = 0.0444) expression were significant prognostic factors.

CONCLUSIONS

These findings suggest that Cyclin B1 expression could be a significant prognostic parameter in NSCLC. The loss of Wee1 expression may have a potential role in promoting tumor progression and may be a significant prognostic indicator in NSCLC.

CT is useful for identifying patients with complicated appendicitis

BACKGROUND AND AIMS

We often come across patients with complicated appendicitis (perforation, abscess formation, or peritonitis) and it is essential to get accurate and detailed information on these patients preoperatively. In this study, we investigated whether or not preoperative computed tomography is useful for identifying these patients.

PATIENTS AND METHODS

Plain and intravenously-contrasted helical computed tomography was obtained preoperatively in 94 (75%) of 125 patients who underwent appendectomy. Twenty-eight (30%) of the 94 patients had complicated appendicitis (Compli(+) group). We compared clinical factors and computed tomography findings of the Compli(+) group with those of 66 other patients (Compli(-) group).

RESULTS

There was no significant difference between the Compli(+) and Compli(-) groups in gender, white blood cell count, the present rate of an enlarged appendix, or appendicolith. Fat stranding and free fluid on computed tomography were significantly associated with complicated appendicitis by both univariate and multilogistic regression analysis. Fourteen (70%) of the 20 patients with fat stranding and free fluid on computed tomography had complicated appendicitis and only 1 (4%) of the 28 Compli(+) patients had neither fat stranding nor free fluid on computed tomography.

CONCLUSION

Our study has indicated that fat stranding and free fluid on computed tomography are significant for complicated appendicitis and helical computed tomography is a powerful tool for identifying patients with complicated appendicitis preoperatively.

Mutation analysis of transforming growth factor beta type II receptor, Smad2, Smad3 and Smad4 in esophageal squamous cell carcinoma

Mutations of the transforming growth factor beta type II receptor (TGFbetaRII) gene and Smad family genes have been observed in several human cancers. However, there has been no report on mutation analysis of the entire coding regions of these genes in esophageal cancer, and the role of these genes in the development of esophageal cancer remains unknown. We performed polymerase chain reaction-single strand conformation polymorphism analysis of TGFbetaRII, Smad2, Smad3 and Smad4 genes and microsatellite assay in 20 esophageal squamous cell carcinomas (ESCC). We detected polymorphisms at exon 2 of Smad3 and intron 6 of Smad4. No mutation was found in TGFbetaRII, Smad2, Smad3 and Smad4 genes. These results suggest that mutation of TGFbetaRII, Smad2, Smad3 and Smad4 genes is a rare event in ESCC.

Analysis of specific gene mutations in the transforming growth factor-beta signal transduction pathway in human ovarian cancer

Several proteins, including transforming growth factor beta (TGF-beta) receptor type I (RI), TGF-beta receptor type II (RII), Smad2, Smad3, and Smad4/DPC4, have been identified in the transduction pathway of the tumor suppressor TGF-beta. Mutations in TGF-beta RI, TGF-beta RII, Smad2, and Smad4/DPC4 genes are associated with several human cancers. The present study examines these gene mutations in 32 human ovarian cancers and 14 patient-matched normal tissues. For the first time, mutations in the Smad2 and Smad4 genes were analyzed in relation to human ovarian cancer. Gene mutations of TGF-beta RI, TGF-beta RII, Smad2, and Smad4 were analyzed using specific primers by PCR-single-strand conformational polymorphism (SSCP), and the results revealed a frameshift mutation at codons 276-277 (CTCTGG-->CTGCGTGG) in exon 5 of TGF-beta RI in 10 of 32 tumor samples (31.3%). This mutation was associated with reduced or absent expression of TGF-beta RI protein and p53 protein in tumor tissues. We detected SSCP variants of TGF-beta RII in exon 2 in 20 of 32 tumors. Sequence analysis of these variants revealed an A to G transition at the seventh band of intron 2. In this A to G polymorphism in intron 2, 12 samples (37.5%) had A/A alleles, 12 (37.5%) had A/G alleles, and 8 (25%) had G/G alleles. We detected Smad2 SSCP variants in exon 4 in 12 of 32 tumors (37.5%). Sequence analysis revealed a 2-bp deletion in the polypyrimidine tract of intron 3, which is located at position -39 to -56 in the splice acceptor site of the intron 3-exon 4 junction. No SSCP variants were detected in the Smad4 gene. These findings suggest that mutations in the TGF-beta RI and in its signal transduction pathway are likely responsible for human ovarian carcinogenesis.

[The incidences of virulence genes in Escherichia coli strains from sporadic diarrheal children]

To investigate the incidence of diarrheagenic Escherichia coli among E. coli strains screened by commercially available O-antigen antisera, we used PCR to isolate 8 virulence genes (eae, bfpA, IpaH, LT, ST, VT1, VT2, and aggR) in 184 E. coli strains sampled from sporadic diarrheal children in our district. eae and bfpA are the localized adherence factor genes of enteropathogenic E. coli (EPEC). IpaH is the invasion antigen gene of enteroinvasive E. coli (EIEC), LT and ST are the toxin genes of enterotoxigenic E. coli (ETEC), VT1 and VT2 are the toxin genes of enterohemorrhagic E. coli (EHEC), and aggR is the adherence factor gene of enteroaggregative E. coli (EAggEC). The results were as follows: eae, 7 (3.8%); bfpA, 0 (0%); IpaH, 0 (0%); LT, 0 (0%); ST, 2 (1.1%); VT, 5 (2.7%); aggR, 8 (4.3%). Seven isolates with eae did not have bfpA, and did not show a localized adherence to HeLa cells. Seven of the 8 isolates with aggR showed aggregative adherence to HeLa cells, while their O-serotypes of them were O111:H21 or O111:HUT. Because of the low incidence of the virulence gene, the commercially available O-antigen antisera was not expected to be useful for the screening of diarrheagenic E. coli, except for EHEC and EAggEC. EAggEC may be important as a pathogen of sporadic diarrhea of children as well as EHEC.

Mutation analysis of the Smad3 gene in human ovarian cancers

The Smad3 gene is a member of the Smad family, vertebrate homologues of Drosophila Mad, and its gene product is a cytoplasmic element in the transforming growth factor-beta (TGF-beta) signaling pathway. Mutations in TGF-beta receptors and their cytoplasmic elements of transduction signals commonly accompany various cancers. Using PCR-SSCP analysis we searched for the presence of Smad3 gene mutations in 36 human ovarian cancers, and found that 15 cases (41. 7%) had a polymorphism at codon 103. Because this mutation was not accompanied by amino acid replacement, the present results show that the mutations in the Smad3 gene are unlikely to be involved in human ovarian cancers.

Mutation analysis of transforming growth factor beta type II receptor, Smad2, and Smad4 in hepatocellular carcinoma

Mutations in the transforming growth factor beta type II receptor (TGFbetaRII), Smad2, and Smad4 genes have been detected in several human cancers. However, there are no reports of mutation analysis of the entire coding regions in these genes in hepatocellular carcinoma, and the roles of these genes in hepatocarcinogenesis remain unknown. We screened 30 hepatocellular carcinomas for mutations of these genes using polymerase chain reaction single-strand conformation polymorphism. We detected no mutations, but did find 3 cases of loss of heterozygosity of chromosome 17p13.1. These results suggest that mutations of the TGFbetaRII, Smad2, and Smad4 genes are rare, and that genetic instability is uncommon in human hepatocellular carcinoma.

Lack of transforming growth factor-beta type II receptor expression in human retinoblastoma cells

Retinoblastoma cells are resistant to transforming growth factor-beta (TGF-beta) activity due to the absence of TGF-beta binding. To further elucidate the mechanism of TGF-beta resistance, we studied the expression of the TGF-beta receptors and SMADs by using the Y79 and WERI-Rb-1 retinoblastoma cell lines. Binding of 125I-TGF-beta1 to serine/threonine kinase receptor type II (TbetaR-II) and TbetaR-I was not seen in the retinoblastoma cells. TbetaR-II mRNA was not expressed in these cells, but TbetaR-I mRNA was detected. Mutation analysis revealed no mutation in the coding region of the TbetaR-II gene, and TbetaR-II mRNA could be induced after the differentiation of Y79 cells. Smad2, Smad3, and Smad4, which are involved in TGF-beta signaling, were expressed in the retinoblastoma cells. Transcriptional activation of the TGF-beta-responsive genes was not seen by the transfection of either receptor cDNA alone but could be induced by transfection of both TbetaR-II and TbetaR-I. These data suggest that the defect in the TGF-beta response is caused by the lack of TbetaR-II in the retinoblastoma cells. In addition, TbetaR-I may be functionally inactivated in these cell lines.

Mutation analysis of the Smad2 gene in human colon cancers using genomic DNA and intron primers

In mammals, one of the Mad homologues, Smad2, was reported to be a mediator of TGF-beta signaling, and was found mutated in some cases of colon and lung cancers. To extend the analysis of this gene, we previously investigated the genomic organization of the human Smad2 gene and defined the structure of 12 exons and flanking introns. In this study, we designed 11 sets of intron-based primers to examine the entire coding region of the Smad2 gene. By the PCR-SSCP method using these primers, we screened genomic DNA sequences of colorectal cancers for mutations of the Smad2 gene. Though there was no mutation within all exons of the Smad2 gene, two of 60 sporadic colorectal cancers displayed deletions in the polypyrimidine tract preceding exon 4. Deletions of this region were also detected in colon cancer cell lines, and were clustered within cells exhibiting microsatellite instability. Deletions in the polypyrimidine tract had various effects on pre-mRNA splicing, but had no effect on the splicing of the Smad2 gene in these cases. However, our data support the idea that the polypyrimidine tract in the splicing acceptor site is a target of mutations in mismatch repair-deficient tumors.

Absence of mutations in the analysis of coding sequences of the entire transforming growth factor-beta type II receptor gene in sporadic human breast cancers

The transforming growth factor-beta (TGFbeta) binds the type II TGFbeta growth factor receptor (TGFbetaRII) to inhibit the growth of most epithelial tissues. Most human colon and gastric cancers with microsatellite instability (MI) have frameshift mutations in polynucleotide repeats within the TGFbetaRII coding region; these mutations truncate the receptor protein and disable the serine/threonine kinase to produce TGF-beta resistance. To further investigate the type, frequency and tissue distribution of TGFbetaRII gene mutations, in this study, we examined 36 sporadic breast cancers. We previously produced eight intron based primer pairs for mutational analysis of the entire coding region of the TGFbetaRII gene. Using these primers, we developed protocols for polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) analysis of PCR products from genomic DNA samples of 36 breast cancer patients and we tested them for microsatellite instability (MI) at eight microsatellite loci. One case demonstrated MI (2.8%) and we found no mutations. These and other recent data indicate that TGFbetaRII mutations are essentially confined to colon and gastric cancers with MI. The narrow spectrum of tissues containing RII mutations illustrates the complexity of genetic checkpoints in human carcinogenesis.

Characterization of the MADH2/Smad2 gene, a human Mad homolog responsible for the transforming growth factor-beta and activin signal transduction pathway

The transforming growth factor beta (TGF-beta) superfamily is a family of multifunctional cytokines that transduce signals via serine/threonine kinase receptors. Recent studies revealed that Mothers against dpp (Mad) in Drosophila and its homologs play important roles in the intracellular signal transduction of the serine/threonine kinase receptors. In mammals, one of the Mad homologs, MADH2 (also termed Smad2), was reported to be a mediator of TGF-beta and activin signaling and was found mutated in some of the colon and lung cancer cases. We describe here the genomic organization of the human MADH2 gene. The gene is composed of 12 exons; 2 exons 1, i.e., exon 1a and 1b, are used separately or in conjunction to form exon 1a-exon 1b-exon 2 alternatively spliced mRNA. The 2 exons 1 are closely located, and the MADH2 mRNAs are transcribed from two promoters in one CpG island. The promoter activity in the 5' upstream sequence was confirmed by the luciferase assay. The 3' end of the mRNA is heterogenous, and we found several polyadenylation signals. Northern blot analysis revealed high expression of the MADH2 mRNA, e.g., in skeletal muscle, heart, and placenta. RT-PCR assay using primers in exons 2 and 4 and direct nucleotide sequencing proved that exon 3 is spliced out in about 10% of MADH2 in human placenta. These data will be valuable for studying the MADH2 function in both normal cells and cancer cells.

Absence of mutatins in the analysis of coding sequences of the entire transforming growth factor beta type II receptor gene in sporadic humangastric cancer using genomic DNA and intron primers

Mutations in the transforming growth factor beta type II receptor (TGFbetaRII) gene have been detected in several human cancers that represent the phenotype of genomic instability. To establish a basis for diagnosis of cancer patients, we previously determined the exon-intron organization of the TGFbetaRII gene. The results indicated that TGFbetaRII protein is encoded by 567 codons in 7 exons. In this study, we further determined the nucleotide sequences surrounding these 7 exons and designed 8 sets of intron-based primers to examine the entire coding region of the TGFbetaRII gene. By using these primers, we screened for mutations of the TGFbetaRII gene in DNAs of 32 sporadic gastric cancer patients in whom one case showed MI+ (3.1%) at two loci. We found no mutations, and these data support other recent evidence that TGFbetaRII mutations rarely occur except in colon and gastric tumors with MI.

Increased prevalence of penicillin-resistant viridans group streptococci in Japanese children with upper respiratory infection treated by beta-lactam agents and in those with oncohematologic diseases

BACKGROUND

Viridans group streptococci, especially penicillin-resistant strains, have been emerging as pathogens of bacteremia in neutropenic patients with hematologic malignancies.

OBJECTIVES

To survey the penicillin susceptibilities of viridans group streptococci in Japanese children with and without oncohematologic diseases and to evaluate the effect of the short term administration of beta-lactam agents on the antibiotic susceptibility.

METHODS

We tested 113 isolates of viridans group streptococci by the microdilution method for the minimal inhibitory concentrations (MICs) to 10 antibiotics. We isolated 40 isolates from the throats of children with an upper respiratory infection (URI) before beta-lactam antibiotic treatment, 32 isolates after the treatment, 33 isolates in hospitalized children with oncohematologic diseases and 8 isolates from blood.

RESULTS

Twenty-five isolates (62.5%) from the children with URI before treatment were penicillin-intermediate or -high level resistant (MIC > or = 0.25 microg/ml). The prevalence of those isolates after antibiotic treatment (87.5%) was significantly increased compared with that before treatment (P = 0.03). The prevalences of the penicillin-high level resistant isolates (MIC > or = 4 microg/ml) in the children with oncohematologic diseases (39.4%) and in the isolates from blood (62.5%) were significantly higher than that in the children with URI before treatment (12.5%) (P < 0.01). Decreased susceptibilities to other beta-lactam agents were observed in the penicillin-high level resistant strains.

CONCLUSIONS

The high prevalence of penicillin-intermediate or -high level resistant viridans group streptococci in healthy Japanese children was documented. The administration of beta-lactam agents decreased the prevalence of penicillin-susceptible isolates in the children with URI. High prevalences of penicillin-high level resistant isolates were observed in the oncohematologic patients and in the isolates from blood.

Evidence that the aberrant alpha 1-->2fucosyltransferase found in colorectal carcinoma may be encoded by Fuc-TIII (Le) gene

The accumulation of alpha 1-->2fucosylated antigens such as Le(b) and Y and the presence of aberrant alpha 1-->2 fucosyltransferase(s) (alpha 12FT) which showed new substrate specificities and must be involved in the accumulation of alpha 1-->2fucosylated antigens in colorectal carcinoma has been observed in our previous studies. In this study, we examined the substrate specificities of purified alpha 12FT from Colo201 cells and COS-1 cells transfected with the Fuc-TIII (Le) gene from a patient with colorectal carcinoma. It was demonstrated that activities of not only the Le gene related alpha 1-->3/4-fucosyltransferase but also the aberrant alpha 12FT were present in the purified preparation and in the extract of transfected COS-1 cells on which the Le(b) activity was expressed. These results suggested that the aberrant alpha 12FT was associated with the Le enzyme and that both enzymes could be encoded by the Fuc-TIII gene.

Possible role of protein kinase C in the regulation of intracellular stability of focal adhesion kinase in mouse 3T3 cells

Effects of various types of protein kinase inhibitor on the adhesion and spreading of BALB/c mouse 3T3 cells and on the phosphorylation and stability of focal adhesion kinase (FAK) in the cells were studied. Inhibitors of protein tyrosine kinases, methyl 2,5-dihydroxycinnamate and herbimycin A, inhibited tyrosine-phosphorylation of FAK and the adhesion of 3T3 cells to fibronectin. Among inhibitors of serine/threonine kinases tested, calphostin C, a specific inhibitor of protein kinase C, inhibited cell spreading rather than cell adhesion, and it induced the decrease of intracellular FAK within 30 min. Inhibitors of tyrosine kinase, A kinase, G kinase, and myosin light chain kinase did not induce such a rapid and specific decrease of FAK. When calphostin C (20 microM) was added to sub-confluent monolayer cultures, serine-phosphorylation of FAK was inhibited by 67% within 2 h, and decrease in the amount of FAK and rounding up of the cells began after 4 h. Label-chase experiments indicated that about 60% of 35S-labeled FAK degraded within 1-2 h after addition of calphostin C to monolayer cultures. These results indicated that serine-phosphorylation of FAK induced by protein kinase C was important in the regulation of metabolic stability of FAK.

Stimulation of tyrosine- and serine-phosphorylation of focal adhesion kinase in mouse 3T3 cells by fibronectin and fibroblast growth factor

Phosphorylation of both tyrosine and serine residues of focal adhesion kinase (FAK) was stimulated by the adhesion of BALB/c mouse 3T3 cells to fibronectin, but phosphorylation of threonine was not detectable. Acidic and basic fibroblast growth factors also stimulated the phosphorylation of serine and tyrosine of FAK in cells adhered to poly-L-lysine, but epidermal growth factor and platelet-derived growth factor did not. A fusion protein of fibronectin and basic fibroblast growth factor effectively induced the phosphorylation of FAK. Phosphorylation of FAK in the rat myoblast L-6 cell line, which lacks fibroblast growth factor receptors, was not stimulated by fibroblast growth factors, suggesting that the interaction of fibroblast growth factors with their receptors might cause the phosphorylation of FAK.

[Nosocomial infections due to methicillin-resistant S. aureus (MRSA) at the Kagoshima University Hospital (2). Susceptibility to antibiotics]

Susceptibility to antibiotics of 123 MRSA strains isolated at the Kagoshima University Hospital in 1989 was examined. The results were as follows: 1) Susceptibility of MRSA strains was excellent to VCM, MINO, and RFP, followed by IMP, CLDM, and CPFX. However, most strains were resistant to PCG, MPIPC, ABPC, CET, CMZ, CZON, GM, and AMK. 2) Five strains highly resistant to RFP were isolated. Three of these strains were isolated on the ward for tuberculosis. This suggests easy development of resistance to RFP by MRSA. 3) Differences in susceptibility to antibiotics between coagulase type II and type VII strains were examined. The cumulative percentage of type II strains susceptible to CLDM (MICs less than 0.5 microgram/ml) was 15.3%, and that of type VII was 45.2%. Strains resistant to CLDM were more frequently isolated among type II than among type VII strains (p less than 0.001). A similar relationship between strains and antibiotics was also found with EM and CPEX. On the other hand, the cumulative percentage of type II strains susceptible to AMK (MICs less than 25 micrograms/ml) was 89.7%, and that of type VII was 9.7%. Strains resistant to AMK were more frequently isolated among type VII than among type II strains (p less than 0.001).

[Nosocomial infections due to methicillin-resistant S. aureus (MRSA) at the Kagoshima University Hospital (1). Coagulase typing of MRSA]

Nosocomial infection due to MRSA at the Kagoshima University Hospital and their coagulase typing were examined using S. aureus (349 strains) clinically isolated in 1989. The results were as follows: 1) S. aureus consisted of 43.6% of MRSA and 56.7% of Methicillin-sensitive S. aureus (MSSA). 2) MRSAs were recovered most frequently from the specimens from the respiratory tract (47.8%). 3) The isolation of MRSA gradually increased in frequency from January to August; however, that of MSSA did not show a similar tendency. 4) The isolation of MRSA was higher in frequency in the surgical wards, the ICU and the pediatric ward. 5) When classified into 8 coagulase types, MRSAs (133 strains) consisted of only 3 types (54.1% of type II, 32.3% of type VII, and 12.0% of type IV), whereas MSSAs contained all coagulase types. As compared with the results of coagulase typing at other institutions, the incidence of type VII was much more frequent at our hospital. 6) A few coagulase types of MRSA appeared in each ward. Also, type II MRSA strains increased in June and July, and type VII MRSA increased in August. However, MSSA strains did not show any similar tendency.

Nucleotide sequence of the gene coding for four subunits of cytochrome c oxidase from the thermophilic bacterium PS3

The gene coding for four subunits of cytochrome aa3-type oxidase was isolated from a genomic DNA library of the thermophilic bacterium PS3 and sequenced. The N-terminus of each subunit was also sequenced to verify the initiation site of the reading frame. The deduced amino acid sequences contained 615 amino acid residues for subunit I (CO1/caaB product), 333 residues for subunit II (CO2/caaA product), 207 residues for subunit III (CO3/caaC product), and 109 residues for subunit IV (CO4/caaD product) after processing. Re-examination of the sequencing of caa revealed a longer open reading frame for CO1, which contains 14 transmembrane segments instead of 12 [Sone et al. (1988) J. Biochem. 103, 606-610], although the main portions of the sequences constituting cytochrome a (FeA), cytochrome a3 (FeB), and CuB are correct. PS3 CO2 has an additional sequence for cytochrome c after the CuA binding protein portion with 2 transmembrane segments, which is homologous to the mitochondrial counterpart. PS3 CO3 has DCCD-binding glutamyl residues but contains only 5 transmembrane segments, unlike the mitochondrial counterpart, which has 7 segments. The subunits of PS3 cytochrome oxidase (aa3-type) show clear similarity in amino acid sequences with those of cytochrome bo-type oxidase from Escherichia coli as well, in spite of the difference of hemes. PS3 CO3 and CO4 are much more similar to E. coli CO3 and CO4 than to mitochondrial CO3 and CO4, respectively.