ClpX and MuB interact with overlapping regions of Mu transposase: implications for control of the transposition pathway

Transposition of phage Mu is catalyzed by an extremely stable transposase-DNA complex. Once recombination is complete, the Escherichia coli ClpX protein, a member of the Clp/Hsp100 chaperone family, initiates disassembly of the complex for phage DNA replication to commence. To understand how the transition between recombination and replication is controlled, we investigated how transposase-DNA complexes are recognized by ClpX. We find that a 10-amino-acid peptide from the carboxy-terminal domain of transposase is required for its recognition by ClpX. This short, positively charged peptide is also sufficient to convert a heterologous protein into a ClpX substrate. The region of transposase that interacts with the transposition activator, MuB protein, is also defined further and found to overlap with that recognized by ClpX. As a consequence, MuB inhibits disassembly of several transposase-DNA complexes that are intermediates in recombination. This ability of MuB to block access to transposase suggests a mechanism for restricting ClpX-mediated remodeling to the proper stage during replicative transposition. We propose that overlap of sequences involved in subunit interactions and those that target a protein for remodeling or destruction may be a useful design for proteins that function in pathways where remodeling or degradation must be regulated.

The structure and organization of the human NPAT gene

Ataxia telangiectasia (AT) is an autosomal recessive gene disorder, and ATM, a housekeeping gene, has been identified as the gene responsible for AT. Recently we found that another housekeeping gene, NPAT, is located upstream of ATM on human chromosome 11. The two housekeeping genes are transcribed in opposite directions and share a 0.5-kb 5' flanking sequence. The structure and organization of NPAT were determined by direct sequencing of cosmid clones carrying the gene and by application of the long and accurate (LA)-PCR method to amplify regions encompassing the exon/intron boundaries and all of the exons. The gene spans at least 44 kb and consists of 18 exons and 17 introns. It has been suggested that AT heterozygotes have an increased risk of developing cancer, especially breast cancer in women. Frequently, loss of heterozygosity at loci on 11q22-q24 has been observed in DNA isolated from tumors of the breast, uterine cervix, and colon, perhaps suggesting the location of a tumor suppressor gene in 11q22-q24. For investigation of the role of NPAT in AT and these tumors with allelic loss of 11q22-q24, appropriate primer sequences and PCR conditions for amplification of all the NPAT exons from genomic DNA were determined. We previously reported that no recombinations are found among Atm, Npat, and Acat1 (acetoacetyl-CoA thiolase) loci as determined by fine genetic linkage mapping of the mouse AT region. The results of the LA-PCR analysis using NPAT- and ACAT-specific primers and human genomic DNA allowed us to map ACAT 12 kb centromeric to NPAT.

Antithrombotic effects of endocardial endothelial cells-comparison with coronary artery endothelial cells

The purpose of this study was to assess the anti-platelet properties of endocardial endothelial cells (EECs) by measuring platelet aggregation after a brief incubation with cultured EECs. EECs were isolated from the right ventricles of porcine hearts and coronary artery endothelial cells (C-ECs) were also isolated from the same animals. After brief incubations (2-min) of platelet suspensions with cultured EEC and CEC monolayers, platelet aggregation in response to thrombin and 6-keto-PGF1 alpha (a stable metabolite of PGI2) content of platelet suspensions were measured. Platelet aggregation was significantly inhibited by a brief incubation of platelet suspensions with EEC and C-ECs monolayers. Pretreatment of EECs and C-ECs with indomethacin (5 x 10(-5) M) restored platelet activity, but pretreatment with N omega-nitro-L-arginine methyl ester (L-NAME, 5 x 10(-5) M) or hemoglobin (1 x 10(-6) M) did not. Platelet/EEC interactions multiplicatively increased the 6-keto-PGF1 alpha content of platelet suspensions and the 6-keto-PGF1 alpha content of platelet suspensions after incubations with EECs correlated significantly with the inhibition of platelet aggregation. Both the anti-aggregation properties and 6-keto-PGF1 alpha production were significantly greater in EECs than in C-ECs. A brief incubation (2-min) with PDGF (10 ng/ml) or TGF-beta (1 and 10 ng/ml) stimulated 6-keto-PGF1 alpha production in EECs but not in C-ECs, although these growth factors stimulated 6-keto-PGF1 alpha production in C-ECs after a longer incubation time (30 or 60 min). In this study, after a brief incubation (2-min) with platelet suspensions, EECs inhibited platelet aggregation mainly through the release of PGI2 but not EDRF. As this anti-aggregation property was significantly greater in EECs than in C-ECs, it is suggested that endocardial endothelial PGI2 may inhibit both intracardiac and intracoronary artery thrombus formation, contributing to the prevention of myocardial ischemia.

Double product response is accelerated above the blood lactate threshold

Catecholamine concentrations are known to increase sharply in the blood at work rates above the blood lactate threshold (LT); thus, we hypothesized that the double product (DP, heart rate-systolic blood pressure product) may also abruptly increase at work rates above the LT. Ninety healthy students performed a stepwise incremental test on a cycle ergometer. The slopes of the two regression lines below and above the LT for the heart rate (HR), the indirectly measured systolic blood pressure (SBP), and the DP, respectively, were compared using VO2 as an independent variable. For all three parameters the slope of the regression line above the LT was significantly higher than that below the LT. Although either the same or a lower slope was found in the HR (N = 23) or SBP (N = 22) responses in some subjects above the LT as compared with that below the LT, a steeper DP slope above the LT was evident in all 90 subjects. The same results were also obtained during 4-min constant work rate exercise sessions at a variety of submaximal intensities performed in a random order in seven subjects. In addition, we established the DP break point (DPBP) determining protocol with a fairly good test-retest reliability (r = 0.951) and a correlation coefficient between the DPBP and the LT (r = 0.900). These results suggest that the DP increases more steeply above the LT, and, as a result, the DPBP is considered to be a valid and useful parameter as a marker of the LT.

The effects of transmural pressure on prostacyclin release from porcine endocardial endothelial cells--comparison with vascular endothelial cells

We assessed the effect of pressure on the release of prostacyclin (PGI2) from cultured endocardial endothelial cells (EECs) and vascular endothelial cells (VECs). EECs were harvested from the right ventricle (RV) and left ventricle (LV) of porcine hearts, and VECs from pulmonary artery (PA), aorta (Ao) and coronary artery (CA). Confluent EECs and VECs were incubated for 30 min under various pressures (0, 50, 100, 150 mmHg) and PGI2 release from each cell was measured. Pressure-induced PGI2 release from LV-EECs was larger than that from RV-EECs. Pressure also increased PGI2 release from both PA- and Ao-VECs, but not from CA-VECs. These findings suggest that endocardium can produce PGI2 in response to pressure and PGI2 released into the coronary blood from the ventricle may play an important role in the prevention of myocardial ischemia.

Sweating economy by graded control in well-trained athletes

Local sweat rates (Msw) at the chest and thigh and the frequency of sweat expulsions (Fsw) were determined in human subjects with (athletes) or without (non-athletes) long-term physical training during moderate bicycle exercise (80 W for 30 min) at ambient thermoneutrality (23 degrees C) and 60% relative humidity. There was a tendency for Msw to be lower in athletes. The rise of Msw with increasing Fsw was significantly less steep and Fsw was also controlled at a significantly lower rate in athletes than in non-athletes. The start of exercise was followed by a temporary decrease in mean skin temperature (Ts) which was less distinct in athletes. The rise in Ts at the end of exercise was significant in athletes (0.80 +/- 0.26 degree C) but not in non-athletes (0.26 +/- 0.33 degree C). The results indicate that long-term physical training leads to improved circulatory heat transfer to the skin and to a more graded nervous control of sweat expulsion and, further, tends to reduce the rate of sweating.

Morphological and flow cytofluorometrical analyses of regenerated rat thymus after irradiation

Reconstituted rat thymuses were studied by immunohistochemistry, transmission electron microscopy (TEM) and flow cytofluorometry on days 0, 1, 2, 3, 5, and 7 after whole-body sublethal irradiation (6 Gy). One day after irradiation, numerous apoptotic cells were seen in the cortical thymus; the percentage of the sub-G1 peak representing apoptotic cells was 8.9% in the DNA content histogram of cytofluorometry. On day 3, the thymic structure had been destroyed and no distinction was drawn between the cortex and medulla. In this stage, few thymocytes but many macrophages were present, and the percentage of the sub-G1 peak reached a peak at 13.0%. Bromodeoxyuridine (BrdU) incorporated cells gradually increased after irradiation, and immunohistochemically numerous apoptotic cells were found primarily in the cortex on day 7. These thymocytes showed some levels of electron density of the nucleus as revealed by TEM. The percentage of S phase cells did not change markedly (20-30%) based on one-color DNA content histograms, but the percentage of early S and S phase cells was extremely high on day 7 (70%). These data indicate that a part of DNA synthetic cells may result in apoptosis. The combination of immunohistochemistry, TEM and flow cytofluorometry to analyze DNA content and BrdU incorporation proved a useful tool for investigating the reconstituted thymus.

Hydroxyl radical scavenging effect of nicaraven in myocardial and coronary endothelial preservation and reperfusion injury

OBJECTIVE

We investigated the efficacy of nicaraven in reducing myocardial as well as coronary endothelial preservation-reperfusion (P/R) injury.

METHODS

In experiment I, isolated rat hearts were mounted on a Langendorff (L) apparatus to estimate the baseline cardiac function. Group 1, 8- and 12-h storage in histidine-tryptophan-ketoglutarate (HTK) solution; group 2, 8- and 12-h storage in HTK solution with superoxide dismutase (2.5 x 10(5) U/I) and catalase (2 x 10(5) U/I); group 3, 8- and 12-h storage in HTK solution with nicaraven (10(-3) M). Following storage for 8 and 12 h at 4 degrees C, they were reperfused and post-preservative cardiac function was evaluated. The hearts were then switched back to L-mode and paced at 330 beats/min. Coronary flow (CF) following perfusion with KHB solution containing 5-hydroxytryptamine (5-HT) and nitroglycerin was also measured. In experiment 2, segments of pig coronary artery were suspended in organ chambers and exposed to hydroxyl radicals in the presence or absence of nicaraven. The sensitivity of relaxation response to bradykinin of the prior-exposed rings was measured.

RESULTS

The recovery of CF and LV dp/dt following 8 h of storage in group 3 was higher than that in group 1, although there were no significant differences in the other parameters of cardiac functional recovery among the groups. The absolute values of cardiac function following 12 h of storage in groups 1-3 were as follows: 6.6 +/- 2.4, 9.1 +/- 0.8, 15.6 +/- 3.1 ml/min of cardiac output (CO); 1.9 +/- 0.9, 2.3 +/- 0.4, 6.0 +/- 2.3 ml/min of aortic flow (AF); 4.5 +/- 1.3, 6.0 +/- 0.5, 9.5 +/- 0.8 ml/min of CF, respectively. The recovery of CO, AF, CF, SP, MP, and left ventricular (LV) dp/dt were significantly improved in group 3, compared with those in group 1. CF and CO in group 3 were higher than those in group 2.5-HT caused vasoconstriction in all groups, but the vasoconstriction in group 3 was less than in group 1. Prior exposure to FeSO4/H2O2 produced significant endothelial damage as reflected by the right-ward shift of the dose-response curve of bradykinin-induced endothelium-dependent relaxation. In the presence on nicaraven, the dose-response curve recovered to the control level.

CONCLUSIONS

Nicaraven may improve coronary endothelial and myocardial function following P/R by its hydroxyl radical scavenging activity.

Effects of recombinant interleukin-1 beta on decorin gene expression in human periodontal ligament fibroblast and its possible transcriptional regulation

Interleukin-1 beta (IL-1 beta) is a potent regulator of osteoprogenitor cells and fibroblasts, and is believed to be responsible for the bone loss and connective tissue breakdown that occurs in periodontitis. Decorin, a major small proteoglycan in the periodontium, has been shown as an important mediator of the organization of the pericellular and extracellular matrix. Since the HPLF play a significant role in the regulation of extracellular matrix metabolism, it was important to clarify the causal relationship between cytokines, HPLF and proteoglycans. We investigated the effect of IL-1 beta on decorin gene expression and its functional regulation to elucidate the intracellular mechanism mediating the action of IL-1 beta. Quiescently confluent HPLF cultures were incubated for different treatment periods with various concentrations of IL-1 beta and/or 10(-4) M cycloheximide (Cx) in culture medium supplemented with 1% charcoal-stripped serum for different treatment periods. Northern hybridization analyses, using decorin cDNA probe, showed that IL-1 beta increased the abundance of decorin mRNA in both a dose- and time-dependent manner. Most of the stimulation was blocked by Cx, indicating that the regulation of decorin gene expression by IL-1 beta may be via an indirect pathway, requiring new protein synthesis which regulates the promoter. Gel mobility shift analyses detected the specific DNA binding activity of a nuclear extract of AP-1, but not NF-kappa B, that could bind to the recognition site of decorin gene promoter fragments with the increased abundance in IL-1 beta treatment groups. These results suggest that the increased transcription of decorin gene by HPLF in the presence of IL-1 beta is mediated at least in part through the interaction of AP-1 with the decorin gene promoter.

[A curative report of multiple organ dysfunction syndrome and disseminated intravascular coagulation due to methicillin-resistant Staphylococcus aureus caused mediastinitis after cardiac surgery]

We experienced a curative case, who was a fifty nine-year old man suffered from multiple organ dysfunction syndrome (MODS) and disseminated intravascular coagulation (DIC) due to Methicillin-resistant Staphylococcus aureus (MRSA) caused-mediastinitis following cardiac surgery against atrial septal defect (ASD) and tricuspid regurgitation. We successfully treated him with mediastinal irrigations by a large quantities of physiological saline containing 1% Povidone iodine (PI) and MRSA sensitive antibiotics as well as artificial supports such as plasma pheresis and hemodialysis against failure organs. It may be due to the prompt treatment with mediastinal irrigation and well timed dosage of sensitive antibiotics against the origin of sepsis that such a serious patient like this case could be recovered from MODS and DIC. In addition, it may be very effective to irrigate with 1% PI against MRSA-caused-mediastinitis.

Alteration of mineral crystallinity and collagen cross-linking of bones in osteopetrotic toothless (tl/tl) rats and their improvement after treatment with colony stimulating factor-1

A common feature of various types of mammalian osteopetroses is a marked increase in bone mass accompanied by spontaneous bone fractures. The toothless (tl/tl) rat osteopetrotic mutation is characterized by drastically reduced bone resorption due to a profound deficiency of osteoclasts and their precursors. An altered bone morphology has also been observed. The mutants cannot be cured by bone marrow transplantation, but skeletal defects are greatly reduced after treatment with colony stimulating factor 1 (CSF-1). The objectives of this study were to characterize mineral and collagen matrices in cancellous and compact bone isolated from long bones of 6-week-old normal littermates, tl/tl osteopetrotic mutants and mutants (tl/tl) treated with CSF-1. There were no differences in bone mineral content, but a significant decrease in the crystallinity of mineral evaluated by the method based on electron paramagnetic resonance spectrometry was observed in all bones of tl/tl mutants as compared to that of controls. Within the collagen matrix, slight decreases in the labile cross-links, but significant increases in the content of the stable cross-links, pyridinoline, and deoxypyridinoline, were observed in both cancellous and compact bone of osteopetrotic mutants. In tl/tl mutants treated with human recombinant CSF-1, the normalization of the crystallinity of bone mineral as well as collagen cross-links was found. Our results indicate that remodeling of bone matrix in tl/tl mutants is highly suppressed, but that after treatment with CSF-1, this activity recovers significantly. Taken together, these data provide further support for the hypothesis that CSF-1 is an essential factor for normal osteoclast differentiation and bone remodelling.

The protein composition of normal and developmentally defective enamel

The development of human enamel involves a complex series of events including the secretion and degradation of a unique extracellular matrix. Ameloblasts progress through a succession of cellular phenotypes executing specialized secretory and regulatory functions. When performing optimally, ameloblasts produce a highly structured and mineralized tissue. Given the elaborate developmental events required for normal enamel formation, it is not surprising that a variety of enamel malformations arise from defects in matrix synthesis, secretion and extracellular processing. Normal matrix secretion and post-secretory processing by ameloblasts can be affected by a variety of hereditary and environmental conditions. These disturbances can result in an abnormal amount and/or composition of matrix proteins, and subsequently, an altered enamel structure and/or mineral content. For example, abnormal matrix removal during enamel maturation apparently contributes to hypomineralization associated with dental fluorosis. Incomplete matrix removal can also occur in several different forms of the hereditary condition amelogenesis imperfects. Specific types of this condition can have retention of substantial enamel protein (e.g. 5% by weight) that is, at least in part, composed of amelogenin and/or its breakdown products. Characterization of the enamel proteins in teeth affected by developmental disturbances can provide insight into the pathogenesis and normal formation of this highly specialized tissue.

Obstructive ileus caused by a swallowed foreign body (a "press-through" package) and preexisting adhesions

A "press-through" package (PTP), because it is large and square-shaped, tends to be caught in the esophagus when swallowed. A rare case of obstructive ileus induced by a PTP that was swallowed by 54-year-old man with a history of diabetes mellitus and acute appendectomy is reported. The PTP was 19 mm x 18 mm and was lodged in the cecum, which was stenosed because of preexisting intestinal adhesions; consequently, the PTP obstructed the ileus. The PTP was surgically removed.

Analysis of sweat evaporation from clothing materials by the ventilated sweat capsule method

The local influence of three clothing materials i.e. silk, cotton and nylon, in (1) full or (2) partial skin contact or (3) at 3 mm from the skin, on sweat evaporation from the chest skin surface of human subjects was studied. The hygrometer-ventilated capsule method was used and sweating was induced at ambient thermoneutrality by a central heat load following lower-leg immersion in water at 43 degrees C. The presence of clothing delayed the rise in capsule relative humidity (CRH) induced by heat loading. During the first 6 min of heating, CRH rose more steeply with clothing that was in full skin contact than with clothing that had partial or no contact. The rate of decrease in CRH from 1 min to 6 min after heating was not influenced by the presence of clothing or by the different degrees of skin contact. The subsequent return of CRH to the pre-heating level was delayed most by cotton, less by silk and least by nylon. For silk and nylon, partial contact with the skin prolonged the return to control conditions, as compared with full skin contact.

Fusion between Jurkat cell and PEO-lipid modified liposome

Direct fusion between Jurkat cell and a liposome modified with poly(ethylene oxide)-bearing lipid (PEO-lipid) was examined using diphtheria toxin fragment A (DTA) as the probe. Only the DTA-loaded liposome modified with PEO-lipid(n = 32) (n is the number of ethylene oxide units) exerted significant cytotoxicity against Jurkat cells, while liposomes lacking either the PEO-lipid or DTA did not. Liposomes modified by the PEO-lipid with shorter PEO chain(n = 5 or 15) did not show any cytotoxicity, irrespective of their DTA-loading. The cytotoxicity was observed even in the presence of cytochalasin B, an inhibitor of endocytosis. Judging from these results, we concluded that the PEO-lipid(n = 32)-modified liposome directly fused with plasma membrane of Jurkat cell.

Microheterogeneity with concanavalin A affinity of serum transferrin in patients with alcoholic liver disease

Microheterogeneity of transferrin (Tf) with concanavalin A (ConA) affinity was investigated by sensitive lectin-affinity electrophoresis and antibody-affinity blotting technique of sera obtained from patients with alcoholic liver disease (ALD) and normal subjects. Serum Tf was separated by ConA into three bands-a strongly ConA-reactive major band (C1), a weakly reactive minor band (C2), and a non-reactive trace band (C3). The C3 fraction was significantly increased in patients with ALD before alcohol abstinence, compared with normal subjects and patients with ALD after 4 weeks of abstinence. Furthermore, a significant correlation was found between the C3 fraction and serum carbohydrate-deficient transferrin or gamma-glutamyl-transpeptidase. These results indicate that the microheterogeneity of serum Tf in patients with ALD may be a more complex abnormality of elongation and processing on the glycans than merely a loss of terminal sialic acids. Determination of the C3 fraction is a useful marker for ALD.

Quantification of serum hepatitis C virus core protein level in patients chronically infected with different hepatitis C virus genotypes

BACKGROUND/AIM

A novel fluorescent enzyme immunoassay (FEIA) for the detection and quantification of serum hepatitis C virus (HCV) core protein was developed. The aim of this study was to evaluate the relation among serum HCV core protein level, HCV RNA level, and HCV genotype in patients with chronic HCV infection.

PATIENTS AND METHODS

Serum HCV core protein, HCV RNA, HCV genotype were determined in 175 patients using the FEIA, branched DNA assay (Quantiplex HCV RNA ver 1.0), and serologically defined genotyping assay, respectively. For the specificity, all 13 patients seronegative for anti-HCV were negative for serum core antigen and HCV RNA by FEIA and bDNA, respectively.

RESULTS

FEIA assay seems to be more sensitive than bDNA for patients with HCV type 2 infection (detection: 83.4% v 63.4%, p < 0.01). There was a good overall correlation between the FEIA and bDNA results. However, when the patients were stratified into their HCV types, a correlation was observed in HCV type 1 but not in type 2 infection. Patients with HCV type 2 infection had a lower serum HCV core protein level (median 56 RFI) compared with type 1 infection (median 149 RFI, p < 0.01). Thirty seven patients subsequently received interferon alpha therapy, patients who showed a complete and sustained response had a lower pretreatment serum HCV core protein level compared with patients who had a relapse and nonresponders (36 v 338 RFI, p < 0.01).

CONCLUSIONS

This study showed that FEIA (1) is a good assay for the detection and quantification of serum HCV core protein level, (2) is also very sensitive in detecting HCV core protein in patients with HCV type 2 infection, and (3) may have a role as a predictor of subsequent response to interferon therapy.

[A successful case of infrarenal abdominal aortic replacement against acute abdominal organ failures and ischemia of bilateral lower limbs following the operation of DeBakey IIIb-type dissecting aneurysm]

We experienced a successful surgical case, who was a 52-year-old man suffered from acute abdominal organ failures and ischemia of bilateral lower limbs following aortic arch replacement against DeBakey IIIb-type dissecting aneurysm. We investigated the abdominal blood flow by DSA via true lumen, which seemed to be obstructed by the increase in blood flow to false lumen. Therefore, to increase in blood flow to true lumen, we performed an urgent infra-renal abdominal aortic replacement successfully.

Protein characterization of fluorosed human enamel

Despite extensive investigation, the development mechanism or mechanisms resulting in dental fluorosis are unknown. Several hypotheses suggest abnormal matrix synthesis, secretion, and delayed and/or defective matrix degradation with retention of enamel protein. The purpose of this study was to characterize the protein composition of fluorosed human enamel. Nine permanent moderately fluorosed (developed in a 3.2 ppm H2O area) and ten permanent normal control teeth (from individuals with < 0.2 ppm F in their drinking water) were evaluated. The enamel fluoride concentration, protein content, and amino acid composition were determined for each tooth. The enamel proteins were further characterized by gel electrophoresis and by Western blot analysis by means of polyclonal antibodies raised against recombinant amelogenin protein. Fluorotic enamel had significantly elevated (p = 0.0001) F levels compared with normal enamel (mean [F-] fluorosed = 431 ppm; mean [F-] control = 62 ppm). While there was a significantly greater protein content by weight in fluorosed enamel compared with normal enamel (mean fluorosed = 0.27%; mean control = 0.11%), the amino acid profiles were similar for fluorosed and normal enamel. Gel electrophoresis showed fluorosed enamel to have a greater diversity of primarily low-molecular-weight proteins compared with normal enamel. Western blot analysis did not indicate retention of amelogenin in either fluorosed or normal enamel. This investigation showed that the protein content of fluorosed enamel was greater than that of normal enamel; however, the amino acid compositions were similar for fluorosed and normal enamel. Furthermore, there does not appear to be retention of significant amounts of amelogenin in fully mature, moderately fluorosed human enamel. Although delayed removal of the enamel matrix proteins may play a role in the hypomineralization defects seen in fluorosed enamel, the majority of these proteins are absent in the mature tissue of these moderately fluorosed teeth.

[Examination of percutaneous minocycline hydrochloride injection therapy for hepatic cyst by one puncture method]

Minocycline hydrochloride (MINO) at a dose of 500 mg (in principle) was injected into each of 11 hepatic cysts/10 cases (mean maximum diameter: 12.6 cm) that exhibited symptoms or a tendency toward growth by percutaneous transhepatic one puncture method, and the relation between therapeutic efficacy and pH of cystic fluid was examined. The efficacy was evaluated by abdominal CT after 3 months, and when a shrink of 50% or more in the maximum diameter was observed, it was judged as marked response. Marked effect was observed in 9 lesions of 11 (82%). This MINO injection therapy by one puncture method is very safe, simple and useful. Reduction in intra-cystic pH was not always related to the therapeutic efficacy, so involvement of cytotoxicity of MINO was suggested in degenerating the cystic epithelial cells.

Heterogeneous structure of the polyubiquitin gene UbC of HeLa S3 cells

The nucleotide sequence of the polyubiquitin gene UbC of HeLa S3 cells and its upstream region was determined and characterized. Recognition sequences for the transcription factors HSF, NF kappa B, AP-1(c-jun), NF-IL6 and Sp1 were found in the upstream control region, a result consistent with the observation of a distinct regulatory response for the UbC gene compared with that of another polyubiquitin gene UbB. Employing a PCR procedure to amplify the entire coding region from genomic DNA, we found a heterogeneity in the repeat number (eight and nine repeats) of the ubiquitin coding units, which resulted from an apparent deletion of either the seventh or the eighth unit in the predominant nine-ubiquitin-unit coding gene. In addition, by comparison with the nucleotide sequence of the UbC gene of human leukocytes previously determined, we found a significant number of nucleotide discrepancies. However, these discrepancies could be substantially reduced by realigning the units so that the first and second ubiquitin units of the sequence determined here are translocated to the boundary between the eighth and the ninth units.