Autoantibodies to NMDA receptor in patients with chronic forms of epilepsia partialis continua

BACKGROUND

Antibody-mediated and cytotoxic T cell-mediated pathogenicity have been implicated as the autoimmune pathophysiologic mechanisms in Rasmussen's encephalitis.

METHODS

The authors investigated autoantibodies against the NMDA glutamate receptor (GluR) epsilon2 subunit and their epitopes in serum and CSF samples from 15 patients with chronic epilepsia partialis continua (EPC), 17 with West syndrome, 10 with Lennox-Gastaut syndrome, and 11 control subjects.

RESULTS

In 15 patients with chronic EPC, we detected NMDA-type GluR epsilon2 autoantibodies in histologically proven Rasmussen's encephalitis (3/3 patients), clinical Rasmussen's encephalitis (6/7 patients), acute encephalitis/encephalopathy (2/3 patients), and nonprogressive EPC (2/2 patients). Serum IgM autoantibodies were found in the early phase of EPC and became negative later in four patients. The autoantibodies were not detected in West syndrome, Lennox-Gastaut syndrome, or controls. Among 10 patients with histologically proven or clinical Rasmussen's encephalitis, epitope analyses showed that the autoantibodies were predominantly against C-terminal epitopes and rarely against N-terminal epitope, with inconsistency in profile during the courses of disease. Epitope recognition spectrum of autoantibodies was broader in CSF than in serum, and the serum or CSF profile showed an increase in number of epitopes as disease progressed in some patients.

CONCLUSIONS

The presence of autoantibodies against NMDA GluR epsilon2 suggests autoimmune pathologic mechanisms but is not a hallmark of Rasmussen's encephalitis. Patients with Rasmussen's encephalitis may have autoantibodies against several neural molecules, and these autoantibodies may be produced in the CNS after cytotoxic T cell-mediated neuronal damage.

A defect in a fatty acyl-CoA synthetase gene, lcf1+, results in a decrease in viability after entry into the stationary phase in fission yeast

An intriguing mutant was isolated in Schizosaccharomyces pombe, which is defective in the maintenance of viability after entry into the stationary phase. In the logarithmic growth phase, the mutant cells grow at the same rate as the parental cells. Upon the onset of the stationary phase, however, the mutant cells lose viability very rapidly. It was found that this phenotype was due to a mutational lesion in the lcf1+ gene, which encodes a long-chain fatty acyl-CoA synthetase. The lcf1Deltamutant shows pleiotropic phenotypes, in that they are also sensitive to high temperature (37 degrees C) and to high salt concentrations (0.9 M KCl) in the medium. Based on the fact that Lcf1 is highly homologous to Faa1 and Faa4 of Saccharomyces cerevisiae, both of which have previously been suggested to play roles in the maintenance of endogenous acyl-CoA pools, the possible function of Lcf1 in S. pombe is discussed.

Microbial community changes during organic solid waste treatment analyzed by double gradient-denaturing gradient gel electrophoresis and fluorescence in situ hybridization

The bacterial community present during semicontinuous treatment of organic solid waste under alkaline and high-temperature conditions was studied. PCR-amplified 16S rDNA fragments were analyzed by double gradient-denaturing gradient gel electrophoresis (DGGE). The band pattern was stable during the steady state of the treatment phase, and the major bands resulting from individual treatments had the same DNA sequence with good reproducibility. No sequence in the DNA database of isolated bacteria showed close similarity to this sequence, the closest relative being Bacillus licheniformis with less than 97% similarity. The conditions for fluorescence in situ hybridization (FISH) were determined without the need to obtain extracts of the bacterial cells. An oligonucleotide probe was designed to detect the microorganisms found in the DGGE analysis. FISH analysis showed that the bacterium corresponding to the major bands accounted for 30% of the total eubacterial cell count at the steady state. These results indicate that this bacterium is a key microorganism in the biodegradation process.

Low-dose ACTH therapy for West syndrome: initial effects and long-term outcome

BACKGROUND

Most Japanese pediatric neurologists attempt other treatments before using adrenocorticotropic hormone (ACTH) therapy for West syndrome (WS), and even then, they use only a low-dose synthetic ACTH to avoid serious adverse effects. In this multi-institutional study, the authors analyzed the initial effects, adverse effects, and long-term outcome in patients treated with low-dose synthetic ACTH in Japan.

METHODS

The medical records of 138 patients with WS, who were treated with low-dose synthetic ACTH therapy for the first time at the authors' institutions between 1989 and 1998, were analyzed.

RESULTS

At the end of ACTH therapy, excellent effect on seizures was noted in 106 of 138 (76%) patients, good effect in 23 (17%), and poor effect in 9 (7%). Initial effects on EEG were excellent in 53 of 138 (38%) patients, good in 76 (55%), and poor in 9 (7%). As for seizure prognosis at the time of follow-up, 51 of 99 (52%) patients were seizure-free, whereas 48 (48%) patients had seizures. Mental outcome was normal in 6 of 98 (6%) patients, mild mental retardation in 16 (16%), moderate mental retardation in 26 (27%), and severe mental retardation in 50 (51%). The initial effects of ACTH on seizures and long-term outcome were not dose dependent (daily dosage 0.005 to 0.032 mg/kg, 0.2 to 1.28 IU/kg; total dosage 0.1 to 0.87 mg/kg, 4 to 34.8 IU/kg). The severity of adverse effects correlated with total dosage of ACTH, and the severity of brain volume loss due to ACTH correlated well with the daily dosage and total dosage of ACTH.

CONCLUSION

Low-dose synthetic ACTH therapy is as effective for the treatment of WS as the higher doses used in previous studies. The dosage of synthetic ACTH used in the treatment of WS can be decreased as much as possible to avoid serious adverse effects.

Genetic analysis of the His-to-Asp phosphorelay implicated in mitotic cell cycle control: involvement of histidine-kinase genes of Schizosaccharomyces pombe

Common histidine-to-aspartate (His-to-Asp) phosphorelay signaling systems involve three types of signaling components: a sensor His-kinase, a response regulator, and a histidine-containing phosphotransfer (HPt) protein. In the fission yeast Schizosaccharomyces pombe, two response regulators, Mcs4 and Prr1, have been identified, and it was shown that they are involved in signal transduction in stress responses. Furthermore, Mcs4 and Prr1 appear to be involved in mitotic cell-cycle control and meiosis, respectively. Recently we have identified Spy1 (also known as Mpr1), which encodes an HPt phosphotransmitter, and reported that Spy1, together with Mcs4, plays a role in cell cycle regulation. In this study, we identified and characterized three genes encoding histidine kinase, named Phk1, Phk2, and Phk3 (S. pombe histidine kinase) (also referred as Mak2, Mak3, and Mak1, respectively). Deletion of individual kinase genes has no apparent phenotypes but multiple deletion of these kinases showed the same phenotype of Spyl (Mpr1)-deficient cells, indicating precocious entry into M phase. These results indicated that three histidine kinases that work upstream of the HPt-transmitter, Spy1 (Mpr1), have a redundant function in cell cycle control.

Predictive value of serum interleukin-6 level in influenza virus-associated encephalopathy

OBJECTIVE

In Japan, >200 children with influenza virus-associated encephalopathy were reported in 1999 and the mortality rate was high. The levels of tumor necrosis factor-alpha (TNFalpha) and interleukin-6 (IL-6) in both CSF and serum were significantly increased in severe cases. The authors found a correlation between elevated serum cytokine levels and mortality and neurologic morbidity.

METHODS

TNFalpha, IL-6, soluble tumor necrosis factor receptor 1 (sTNF-R1), interferon-gamma (IFNgamma), and IL-2 were measured by the ELISA method in sera from six children with encephalopathy before and during therapy, and in six age-matched controls with influenza type A virus infection.

RESULTS

The increases in the serum TNFalpha, IL-6, and sTNF-R1 levels were statistically significant at the onset of symptoms before therapy, but the IL-6 level was most useful for diagnosis. The serum IL-6 levels were >6,000 pg/mL in children with brain stem dysfunction, about 150 pg/mL in children without brain stem dysfunction, and <80 pg/mL in controls. The time course of the serum IL-6 level also reflected the clinical condition. Once the serum IL-6 level was increased to >15,000 pg/mL, none of the children survived. The lower the maximal serum IL-6 level, the milder the CNS sequelae.

CONCLUSION

The serum IL-6 level may be the most useful indicator for the diagnosis and the clinical severity of influenza virus-associated encephalopathy.

Different responses to auditory and somaesthetic stimulation in patients with an excessive startle: a report of pediatric experience

OBJECTIVES

Children with cerebral injury often exhibit brief muscle contraction to a variety of stimuli. However, it remains to be determined whether or not the pattern of the reaction is stereotypical irrespective of the site stimulated. To answer this question, we studied electromyographic (EMG) responses to three types of stimuli in children.

METHODS

The EMG responses of cranial and limb muscles were recorded after acoustic or somaesthetic stimulation in 6 patients and 23 control subjects.

RESULTS

Acoustic stimuli evoked patterned motor activity with a rostrocaudal progression. Nose-tapping stimuli elicited reflex EMG activity in the VIIth cranial muscles that was similar to the R1 component of the electrical blink reflex. Sternum-tap stimuli evoked motor activity in the sternocleidomastoid and arm muscles, and this reflex was probably mediated through the cervical cord (H-reflex). Moreover, late reflexes were evoked following these early reflexes in the patients. In particular, atypical forms of myoclonic jerks were evoked on sternum-tap stimuli.

CONCLUSIONS

Many types of primitive reflexes were evoked following three types of stimuli. These reflexes included startle reflex, trigeminomotor reflex, H-reflex and atypical forms of myoclonus, and they were enhanced in the patient group. There are many startle-mimicking reflexes.

A novel feature of the multistep phosphorelay in Escherichia coli: a revised model of the RcsC --> YojN --> RcsB signalling pathway implicated in capsular synthesis and swarming behaviour

In this study, we re-investigated the previously characterized RcsC (sensor His-kinase) --> RcsB (response regulator) phosphorelay system that is involved in the regulation of capsular polysaccharide synthesis in Escherichia coli. The previously proposed model hypothesized the occurrence of a direct phosphotransfer from RcsC to RcsB in response to an unknown external stimulus. As judged from the current general view as to the His --> Asp phosphorelay, this RcsC --> RcsB framework is somewhat puzzling, because RcsC appears to contain both a His-kinase domain and a receiver domain, but not a histidine (His)-containing phosphotransmitter domain (e.g. HPt domain). We thus suspected that an as yet unknown mechanism might be underlying in this particular His --> Asp phosphorelay system. Here, we provide several lines of in vivo and in vitro evidence that a novel and unique His-containing phosphotransmitter (named YojN) is essential for this signalling system. A revised model is proposed in which the multistep RcsC --> YojN --> RcsB phosphorelay is implicated. It was also demonstrated that this complex signalling system is somehow involved in the modulation of a characteristic behaviour of E. coli cells during colony formation on the surface of agar plates, namely swarming.

The Arabidopsis sensor His-kinase, AHk4, can respond to cytokinins

His-to-Asp (His-->Asp) phosphorelay mechanisms are presumably involved in propagation of certain environmental stimuli, including phytohormones, in Arabidopsis thaliana. In addition to the previously characterized His-kinases, namely, the ETR1 family of ethylene receptors, CKI1 cytokinin-sensor, and ATHK1 osomo-sensor, this higher plant has three more His-kinases (named AHK2, AHK3, and AHK4). By employing the well-known His-->Asp phosphorelay systems in both the fission yeast and Escherichia coli, evidence is presented showing that the AHK4 His-kinase has an ability to serve as a cytokinin-responsive environmental sensor. Taking advantage of this AHK4-dependent His-->Asp phosphorelay system in E. coli, a phosphorelay interaction between the Arabidopsis His-kinase and histidine-containing phosphotransmitters (AHPs) was also demonstrated for the first time.

Response function of an irregular oscillator

Properties of the response functions for a two-dimensional quartic oscillator are studied based on the diagonalization of the Hamiltonian in a large model space. In particular, response functions corresponding to a given momentum transfer are studied for different values of the coupling parameter in the Hamiltonian. The latter controls regular or chaotic nature of the spectra and eigenstates of the system. Fluctuation properties of the energy-strength correlation of the response are investigated. Even when the statistical properties of the system indicate an almost completely chaotic character, there remains a typical structure in the response function similar to that in the regular system. The nature of this structure is studied in some detail.

The Prr1 response regulator is essential for transcription of ste11+ and for sexual development in fission yeast

Schizosaccharomyces pombe expresses a putative transcription factor, named Prr1, which is intriguing in the sense that it contains a bacterial type of phospho-accepting receiver domain, preceded by a mammalian heat shock factor (HSF2)-like DNA-binding domain. The receiver domain is most probably involved in an as yet unidentified histidine-to-aspartate (His-to-Asp) phosphorelay pathway in S. pombe. In this study, the structure, function, and cellular localization of Prr1 were assessed in the context of oxidative stress and His-to-Asp phosphorelay. As the most intriguing result of this study, we found that Prr1 is essential not only for the expression of genes induced by oxidative stress (e.g., ctt1+ and trr1+), but also for the expression of ste11+, which in turn is responsible for the expression of a variety of genes required for sexual development. Accordingly, Prr1-deficient cells are not only hypersensitive to oxidative stress, but also severely defective in conjugation and/or spore formation. These results suggested that the transcription factor Prr1 plays a pivotal role in an as yet unknown signal transduction pathway that is implicated in sexual differentiation. These findings are discussed with special reference to the well-characterized transcription factors Pap1 and Atf1 of S. pombe.

Identification and characterization of a novel gene, hos2+, the function of which is necessary for growth under high osmotic stress in fission yeast

hos2 mutants of the fission yeast Schizosaccharomyces pombe showed the phenotype of high osmolarity sensitivity for growth. An S. pombe strain carrying the hos2-M10 allele cannot form colonies on agar plates containing 2 M glucose, but the parental strain can do so very well, as demonstrated previously. In this study, the hos2+ gene was identified as one that encodes a small protein of 94 amino acids, which shows no sequence similarity to any other proteins in the current databases. The hos2-M10 mutation resulted in Gln-62 to TAG-termination codon. A Hos2-defective (hos2delta) strain, which we then constructed, showed the phenotype of high osmolarity sensitivity, as in the case of the original hos2-M10 mutant. For this hos2delta mutant, three multicopy suppressor genes were isolated and one of which was identified as the pgk1+ gene, encoding a phosphoglycerate kinase.

A novel regulatory role of glucose transporter of Escherichia coli: membrane sequestration of a global repressor Mlc

External glucose stimulates transcription of several genes including ptsG encoding IICB(Glc), a membrane component of the phosphotransferase system (PTS), by relieving the negative regulation of a global repressor Mlc in Escherichia coli. We investigate here how glucose modulates Mlc action. The Mlc-mediated repression is eliminated by a ptsI mutation, while Mlc is constitutively active in a ptsG mutant. We show that IICB(Glc)-FLAG interacts physically with Mlc in crude extracts prepared from cells in which IICB(Glc) is supposed to exist as the non-phosphorylated form. The IICB(Glc)-Mlc interaction is no longer observed when IICB(Glc) is phosphorylated. Exogenously added purified Mlc binds to purified IICB(Glc)-FLAG. We also demonstrate that Mlc is associated with membrane when IICB(Glc) is dephosphorylated while it is in the cytoplasm when IICB(Glc) is phosphorylated or absent. We conclude that IICB(Glc) regulates the cellular localization of Mlc, depending on its phosphorylation state, which is determined by the availability of external glucose. Thus, glucose induces the transcription of Mlc-regulated promoters by sequestering Mlc to the membrane through dephosphorylation of IICB(Glc).

Spy1, a histidine-containing phosphotransfer signaling protein, regulates the fission yeast cell cycle through the Mcs4 response regulator

Common histidine-to-aspartate (His-to-Asp) phosphorelay signaling systems involve three types of signaling components: a sensor His kinase, a response regulator, and a histidine-containing phosphotransfer (HPt) protein. In the fission yeast Schizosaccharomyces pombe, two response regulators, Mcs4 and Prr1, have been identified recently, and it was shown that they are involved in the signal transduction implicated in stress responses. Furthermore, Mcs4 appears to be involved in mitotic cell-cycle control. However, neither the HPt phosphotransmitter nor His kinase has been characterized in S. pombe. In this study, we identified a gene encoding an HPt phosphotransmitter, named Spy1 (S. pombe YPD1-like protein). The spy1(+) gene showed an ability to complement a mutational lesion of the Saccharomyces cerevisiae YPD1 gene, which is involved in an osmosensing signal transduction. The result from yeast two-hybrid analysis indicated that Spy1 interacts with Mcs4. To gain insight into the function of Spy1, a series of genetic analyses were conducted. The results provided evidence that Spy1, together with Mcs4, plays a role in regulation of the G(2)/M cell cycle progression. Spy1-deficient cells appear to be precocious in the entry to M phase. In the proposed model, Spy1 modulates Mcs4 in a negative manner, presumably through a direct His-to-Asp phosphorelay, operating upstream of the Sty1 mitogen-activated protein kinase cascade.

SsrA-mediated tagging and proteolysis of LacI and its role in the regulation of lac operon

SsrA RNA of Escherichia coli, also known as 10Sa RNA or tmRNA, acts both as tRNA and mRNA when ribosomes are paused at the 3' end of an mRNA lacking a stop codon. This process, referred to as trans-translation, leads to the addition of a short peptide tag to the C-terminus of the incomplete nascent polypeptide. The tagged polypeptide is then degraded by C-terminal-specific proteases. Here, we focused on endogenous targets for the SsrA system and on a potential regulatory role of SsrA RNA. First, we show that trans-translation events occur frequently in normally growing E. COLI: cells. More specifically, we report that the lacI mRNA encoding Lac repressor (LacI) is a specific natural target for trans-translation. The binding of LacI to the lac operators results in truncated lacI mRNAs that are, in turn, recognized by the SsrA system. The SsrA-mediated tagging and proteolysis of LacI appears to play a role in cellular adaptation to lactose availability by supporting a rapid induction of lac operon expression.

A rare variant of the radial artery: clinical considerations in raising a radial forearm flap

A rare vascular anomaly of the radial artery encountered during elevation of a radial forearm free flap is reported in this paper. We discovered a superficial radial artery which bifurcated from the deep radial artery 4 cm below the antecubital fossa. The blood supply to the proximal radial forearm flap was thought to be from the superficial radial artery, and to the distal forearm flap from both arteries. Ascertaining the course of the radial artery pre- and intraoperatively and careful dissection of the artery are essential to minimise problems of flap transfer.

Identification and characterization of a novel gene, hos3+, the function of which is necessary for growth under high osmotic stress in fission yeast

hos3 mutants of the fission yeast Schizosaccharomyces pombe showed the phenotype of high osmolarity sensitivity for growth. An S. pombe strain carrying the hos3-M26 allele cannot form colonies on agar plates containing 2 M glucose, but the parental strain can do so very well, as demonstrated previously. The hos3+ gene was cloned and identified as one that encodes a small protein of 94 amino acids, which shows no sequence similarity to any other proteins in the current databases. A hos3delta strain, which we then constructed, had the phenotype of high osmolarity sensitivity, as in the case of the original hos3-M26 mutant. More interestingly, when these hos- cells were grown in the non-permissive growth condition in the presence of 2 M glucose, we found that unusually many septated cells were accumulated after a prolonged incubation. A multicopy suppressor gene for hos- mutations was also isolated and identified as the dsk1+ gene encoding a protein kinase, which was previously suggested to be implicated in a process of the mitotic regulation of S. pombe. The function of the hos3+ gene is discussed from these results.

Analysis of measles virus binding sites of the CD46 gene in patients with subacute sclerosing panencephalitis

Measles virus (MV) binding sites of the CD46 gene were sequenced in patients with subacute sclerosing panencephalitis (SSPE) and in controls. There were 3 novel polymorphisms, including C/T at nucleotide position 38 (C/T38), G/A at position 176 (G/A176), and C/T at position 453 (C/T453), at allele frequencies of.97:.03, .99:.01, and.97:.03, respectively. The G/A176 polymorphism causes an Arg/Gln amino acid change within the essential binding sites of MV, whereas the C/A38 polymorphism causes a Ser/Phe change outside the MV binding sites. The C/T453 polymorphism does not produce an amino acid change. Two of the 40 SSPE patients and 2 of the 32 controls had both C/T38 and C/T453 polymorphisms in heterozygous patterns. One control subject, but no SSPE patients, had the G/A176 polymorphism in a heterozygous pattern. Thus, it is not likely that CD46 gene alteration has a role as a host susceptibility factor in the development of SSPE.

Measles virus-specific T helper 1/T helper 2-cytokine production in subacute sclerosing panencephalitis

Live measles virus-specific T helper 1/T helper 2-cytokine productions by peripheral blood mononuclear cells in response to live measles, mumps or varicella virus were measured in 15 patients with subacute sclerosing panencephalitis and 15 controls by enzyme-linked immunosorbent assays. Most patients with subacute sclerosing panencephalitis had a defect in measles virus-specific production of interferon-gamma, one of the T helper 1 type cytokines, despite persistent presence of measles virus, with preserved interleukin-10 (T helper 2 type cytokine) synthesis. Patients with subacute sclerosing panencephalitis were divided into two groups: responders (group A) with significant interferon-gamma production (>20 pg/mL) in response to live measles virus and non-responders (group B) with a little or no interferon-gamma production. Comparison of the clinical courses between groups A and B revealed that all the patients of group A retained receptive function for a long time, while most patients of group B lost the function rapidly (P<0.01). An inverse correlation between interferon-gamma production by peripheral blood mononuclear cells and disease progression suggested that interferon-gamma plays an antiviral role in subacute sclerosing panencephalitis.

The cta3+ gene that encodes a cation-transporting P-type ATPase is induced by salt stress under control of the Wis1-Sty1 MAPKK-MAPK cascade in fission yeast

In Schizosaccharomyces pombe, the Wis1-Sty1 MAP (mitogen-activated protein) kinase signaling cascade is known to play a major role in cellular adaptation to adverse external stimuli, including osmotic stress, oxidative stress, nutrient deprivation, DNA-damaging agents, and heat stress. Nonetheless, it is not known whether or not this particular MAPK cascade is also involved in response to the most common stress, salinity. In this study, we provide evidence that the Wis1-Sty1 MAP cascade is implicated in salt stress response through regulating expression of a salinity-inducible gene. The downstream target gene thus identified is the cta3+ gene, which encodes a cation-transporting P-type ATPase. The salt stress-responsive nature of cta3+ expression was characterized extensively. It was found that not only the Sty1 MAP kinase but also the Atf1 transcription factor is crucial for the inducible expression of cta3+. As far as we know, this is the first instance that the stress-activated Wis1-Sty1 MAPK cascade plays a role in salt stress response in S. pombe.

Negative regulation of the pts operon by Mlc: mechanism underlying glucose induction in Escherichia coli

BACKGROUND

The pts operon of Escherichia coli consists of three genes ptsH, ptsI and crr, each encoding for central components of the phosphoenolpyruvate: carbohydrate phosphotransferase system, HPr, enzyme I and IIAGlc, respectively. Transcription of the pts operon is stimulated when glucose is present in the culture medium. One of the two major promoters, P0, is responsible for this glucose induction. However, no regulatory protein responsible for the glucose induction of the pts operon has been identified yet and molecular mechanism by which glucose stimulates the pts transcription is not known.

RESULTS

We found by Northern blotting that the pts mRNA levels in cells lacking Mlc, a new global repressor of carbohydrate metabolism, were increased without external glucose and that the addition of glucose had no effect on the pts mRNA levels in the mutant cells. Western blotting revealed that the enzyme I level in the mlc- cells was also elevated without glucose and no further increase in the enzyme I level was observed in the presence of glucose. S1 analysis revealed that transcription of the glucose-sensitive promoter, P0, occurs constitutively in the mlc- cells independently from the external glucose. In vitro transcription studies indicated that Mlc strongly inhibited P0 transcription. DNase I footprinting experiment revealed that Mlc bound to P0 promoter region to prevent RNA polymerase binding at P0.

CONCLUSION

We conclude that Mlc is a repressor for the pts transcription acting as a major regulatory protein involved in the glucose induction of pts operon. We propose that glucose induces the pts transcription by modulating the Mlc activity. The mechanism by which glucose modulates the Mlc action remains to be studied.

An inactive open complex mediated by an UP element at Escherichia coli promoters

A specific interaction between the alpha subunit of RNA polymerase and an A+T-rich upstream sequence (UP element) stimulates transcription at some promoters in Escherichia coli. We found that RNA polymerase formed a heparin-resistant nonproductive initiation complex at the malT promoter which has an A+T-rich upstream sequence that begins 9 bp upstream of the -35 region. Substitution of other sequences for the A+T-rich sequence eliminated both the formation of heparin-resistant complexes and alpha binding to the malT promoter. A 5-bp deletion between the A+T-rich sequence and the -35 region increased promoter activity. The UP element derived from the rrnB P1 promoter stimulated transcription of the malT core promoter when placed 4 bp upstream from the malT -35 region, but insertion of an additional 4 bp between the rrnB P1 UP element and the -35 element eliminated transcription activity without eliminating heparin-resistant complex formation. Similar UP element effects were observed in hybrids with the lac core promoter, even though the region around the transcription start site was melted in both productive and nonproductive complexes. We conclude that UP elements can mediate the formation of both productive and nonproductive open complexes, depending on their location with respect to the core promoter.