Interaction of hepatitis B virus X protein with a serine protease, tryptase TL2 as an inhibitor

X protein of hepatitis B virus (HBV) transactivates transcription of various viral and cellular genes. It has been suggested that X protein plays a major role in hepatocarcinogenesis by HBV. The protein possesses amino acid sequence homology to the functionally essential domain of Kunitz-type serine protease inhibitors. This Kunitz domain-like sequence in X protein is indispensable for the transactivation function. To clarify whether X protein has a serine protease inhibitor activity, a search was made for serine proteases which interact with, but not degrade X protein. Tryptase TL2, one of serine proteases in hepatic cells, was found to directly interact with X protein without degradation. Moreover, the activities of tryptase TL2 and an analogous protease were substantially inhibited by X protein. These results suggest that transactivation function of X protein is exerted by modulation of the hepatic serine protease activity, giving rise to quantitative or qualitative change of cellular transcription factor(s) through protection from proteolytic degradation and/or suppression of processing.

Antihypertensive property and renal protection by shichimotsu-koka-to extract in salt-induced hypertension in Dahl strain rats

We determined whether or not the kampo formula, Shichimotsu-koka-to extract, attenuates the development of salt-induced hypertension and provides renal protection against hypertensive injury in Dahl salt-sensitive (Dahl S) rats. A six-week treatment using this formula dose-dependently decreased the systolic blood pressure in Dahl S rats fed a high-salt (2% NaCl) diet. This blood pressure reduction was associated with a decrease in the thickness of the aortic wall. Renal function was not altered with this treatment; however, glomerular sclerotic lesions in the kidney were significantly attenuated. Neither arterial nor tubular lesions were affected. These data suggest that Shichimotsukoka-to extract exhibits an antihypertensive effect which is associated with partial resolution of glomerular sclerosis in the kidney.

Binding characteristics of (-)-(R)-2-aminomethylpyrrolidine(1,1-cyclobutanedicarboxylato)-2-platin um(II) to DNA, RNA and protein molecules in HeLa cells and its lethal effect: comparison with cis- and trans-diamminedichloroplatinums(II)

HeLa S-3 cells were treated with 195mPt-radiolabeled (-)-(R)-2-aminomethylpyrrolidine(1,1-cyclobutanedicarboxylato++ +)-2-platinum(II) (DWA2114R) under various conditions, and the relationship between the lethal effect of the agent and the number of platinum (Pt) atoms binding to DNA, RNA and proteins was examined. The values of mean lethal concentration for the cells treated with DWA2114 at 37 degrees C for 1, 2 and 3 h were 137.3, 75.10 and 51.17 microM, respectively. Cells were treated identically and the numbers of Pt atoms combined with DNA, RNA and protein molecules were determined after fractionation of the cells. In this way, the D0 values (D0, dose that would give an average of one lethal event per member of the population), expressed as the drug concentration, were substituted for the number of Pt atoms combined with each fraction. The target volumes, the efficacy of Pt atom to kill cells expressed as the reciprocals of the D0 values, were then calculated for each fraction. Our findings suggested that DNA was the primary target molecule for cell killing by DWA2114R. The target volumes for DNA were 3.36 x 10(4), 4.00 x 10(4) and 4.10 x 10(4) nucleotides for 1-, 2- and 3-h treated cells, respectively. The cell-killing effects of DWA2114R were lower than those of cis-diamminedichloroplatinum(II) (CDDP) by factors of 1.54, 1.42 and 2.51 for 1-, 2- and 3-h treatments at 37 degrees C, respectively, in terms of the target volume, while those in terms of the mean lethal dose (D0) were 14.8, 11.2 and 16.0, respectively. The efficacy of DWA2114R in killing the cells was 2.6 times greater than that of CDDP in the 3-h treatment at 0 degrees C.

Wnt-3a regulates somite and tailbud formation in the mouse embryo

Amphibian studies have implicated Wnt signaling in the regulation of mesoderm formation, although direct evidence is lacking. We have characterized the expression of 12 mammalian Wnt-genes, identifying three that are expressed during gastrulation. Only one of these, Wnt-3a, is expressed extensively in cells fated to give rise to embryonic mesoderm, at egg cylinder stages. A likely null allele of Wnt-3a was generated by gene targeting. All Wnt-3a-/Wnt-3a- embryos lack caudal somites, have a disrupted notochord, and fail to form a tailbud. Thus, Wnt-3a may regulate dorsal (somitic) mesoderm fate and is required, by late primitive steak stages, for generation of all new embryonic mesoderm. Wnt-3a is also expressed in the dorsal CNS. Mutant embryos show CNS dysmorphology and ectopic expression of a dorsal CNS marker. We suggest that dysmorphology is secondary to the mesodermal and axial defects and that dorsal patterning of the CNS may be regulated by inductive signals arising from surface ectoderm.

The involvement of dopamine in the regulation of steroidogenesis in rat ovarian cells

To investigate a role for dopamine (DA) in steroidogenesis in the rat ovary, ovarian cells of pregnant-mare-serum gonadotropin (PMSG)-treated rats were incubated with DA agonists, antagonists, adrenergic drugs and beta-blocker for 1 h. DA, norepinephrine (NE) and isoproterenol (Iso) increased the level of progesterone (P4) and cAMP in the conditioned medium. D1 agonists (SKF38393, SKF82526J, CY208-243) increased P4 secretion, while the D2 agonist, bromocriptine, showed no significant effect on P4 secretion. The effect of NE or Iso was inhibited by the beta-blocker propranolol (Pro), but was not suppressed by the D2 antagonist, domperidone. The effects of D1 agonists were suppressed by bulbocapnine (Bul), while neither Pro nor the D2 antagonist, domperidone, affected the levels of P4. The D1 receptor was demonstrated in the PMSG-treated rat ovary, and its Bmax was 1.33 fmol/mg tissue and the Kd was 0.357 nM. These results suggest that DA has a direct stimulatory effect on P4 secretion in PMSG-treated rat ovarian cells through they D1 receptor. The observed action may indicate a physiological role for DA in the regulation of ovarian functions in rats.

Effects of gonadotropin-releasing hormone agonist on steroidogenesis in the rat ovary

To assess the regulatory roles of gonadotropin-releasing hormone (GnRH) in ovarian function, the kinetics of the ovarian GnRH receptor and the effects of the GnRH superagonist buserelin on steroidogenesis in ovarian cell culture were examined. Scatchard analysis of buserelin-binding to crude ovarian cell membrane revealed a specific high-affinity GnRH receptor. Buserelin together with follicle-stimulating hormone stimulated estradiol (E2) production in immature follicles in hypophysectomized and DES-treated rats. On the other hand, applied to developing follicles of rats treated with pregnant-mare-serum gonadotropin buserelin suppressed E2 production to terminate follicle maturation and simultaneously stimulated progesterone (P4) production to induce luteinization. With ovarian cells luteinized by human chorionic gonadotropin in vitro, buserelin suppressed production of both P4 and E2, leading to luteolysis. Buserelin affected steroid production by modulating activities of key enzymes in steroid synthesis. These findings indicate that buserelin action depended on the gonadotropin priming of ovarian cells, and suggest the possible involvement of GnRH in the regulation of steroidogenesis throughout the ovulatory cycle.

De novo synthesis of phospholipase A2 and prostacyclin production by proliferating rat smooth muscle cells

We investigated the role of phospholipase A2 (PLA2) in cell cycle-dependent alterations of endogenous prostacyclin (PGI2) synthesis in aortic smooth muscle cells in culture (VSMC) from Wistar Kyoto rats. Randomly cycling VSMC generated more PGI2 than the stationary cells. Cell cycle analysis showed that PGI2 production capacity was increased from the G0/G1 through the early DNA synthetic (S) phases. Enzyme analysis revealed that, although there were different mechanisms underlying this increase in the PGI2 production during the G0/G1, the peak at 4 hours coincided with a sharp increase in PLA2 activity. This increase in PLA2 activity was preceded by an increased expression of functional PLA2 messenger RNA, and protein synthesis inhibition prevented most of the increase in PGI2 production at 4 hours. These data indicate that endogenous PGI2 generation is mainly increased during the G0/G1 period and that this event is secondary to de novo synthesis of PLA2 and probably, at least in part, to cyclooxygenase induction. This mechanism provides a negative feedback regulating VSMC proliferation.

Inhibition of protein synthesis and antiproliferative effect of the angiotensin converting enzyme inhibitor trandolaprilat in rat vascular smooth muscle cells

OBJECTIVE

To investigate the effect of the angiotensin converting enzyme (ACE) inhibitor trandolaprilat on vascular smooth muscle cell growth, and to analyse its mechanism of action.

DESIGN

Aortic vascular smooth muscle cells (VSMC) from Wistar-Kyoto rats were cultured, and cell proliferation was analysed using a cell synchrony technique.

METHODS

Proliferative activity was assessed by [3H]-thymidine uptake and doubling time. Protein synthesis was assessed by [3H]-leucine incorporation. Actin formation was measured using sodium dodecylsulphate-polyacrylamide slab gel electrophoresis and a densitometric assay. The effect of trandolaprilat on translational protein synthesis was also examined using the cell-free protein synthesis system of reticulocyte lysate and messenger RNA from VSMC.

RESULTS

Trandolaprilat decreased [3H]-thymidine uptake and increased the doubling time of randomly cycling VSMC. The cell synchrony study revealed that this antiproliferative effect was due to increased transition time from S to G2-M. Decreased cell cycle progression during G2-M was reflected by inhibition of cellular protein synthesis during this period. Cellular protein in randomly cycling VSMC was also decreased by trandolaprilat. This decreased protein synthesis was probably produced by inhibition of RNA translation.

CONCLUSIONS

The ACE inhibitor trandolaprilat reduces VSMC proliferation by lengthening the G2-M phase of the cell cycle, and produces a decrease in cellular protein content. This effect is probably mediated by inhibition of protein synthesis at the translational level.

A Chlamydomonas outer arm dynein mutant with a truncated beta heavy chain

A new allele of the Chlamydomonas oda4 flagellar mutant (oda4-s7) possessing abnormal outer dynein arms was isolated. Unlike the previously described oda4 axoneme lacking all three (alpha, beta, and gamma) outer-arm dynein heavy chains, the oda4-s7 axoneme contains the alpha and gamma heavy chains and a novel peptide with a molecular mass of approximately 160 kD. The peptide reacts with a mAb (18 beta B) that recognizes an epitope on the NH2-terminal part of the beta heavy chain. These observations indicate that this mutant has a truncated beta heavy chain, and that the NH2-terminal part of the beta heavy chain is important for the stable assembly of the outer arms. In averaged electron microscopic images of outer arms from cross sections of axonemes, the mutant outer arm lacks its mid-portion, producing a forked appearance. Together with our previous finding that the mutant oda11 lacks the alpha heavy chain and the outermost portion of the arm (Sakakibara, H., D. R. Mitchell, and R. Kamiya. 1991. J. Cell Biol. 113:615-622), this result defines the approximate locations of the three outer arm heavy chains in the axonemal cross section. The swimming velocity of oda4-s7 is 65 +/- 8 microns/s, close to that of oda4 which lacks the entire outer arm (62 +/- 8 microns/s) but significantly lower than the velocities of wild type (194 +/- 23 microns/s) and oda11 (119 +/- 17 microns/s). Thus, the lack of the beta heavy chain impairs outer-arm function more seriously than does the lack of the alpha heavy chain, suggesting that the alpha and beta chains play different roles in outer arm function.

Possible radical scavenging properties of cicletanine and renal protection in Dahl salt sensitive rats

Much interest in cicletanine, a novel antihypertensive drug, has grown because it uniquely stimulates prostacyclin (PGI2) production and may, thereby, provide further cardiovascular protection. We postulated that cicletanine may be an antioxidant, and assessed its ability to protect the kidney in Dahl salt-sensitive (Dahl S) rats on a high salt diet. Cicletanine eradicated in vitro a stable radical, DPPH, and decreased the lipid peroxidation both in rat brain homogenate and in a xanthine-xanthine oxidase (X-XOD) superoxide generating system. Furthermore, cicletanine attenuated the inhibition of PGI2 synthase activity by 15HPETE. However, cicletanine did not exhibit superoxide dismutase-like activity in X-XOD system, suggesting that it behaves primarily as a hydroxy radical scavenger. A 6 week cicletanine treatment reduced blood pressure in Dahl S rats fed a high salt diet, and ameliorated functional and morphological injury to the kidney. This attenuation of glomerular sclerosis correlated with the attenuation of lipid peroxidation in the kidney homogenate. These data indicate that cicletanine is an antioxidant that protects the kidney from salt-induced hypertension in Dahl salt-sensitive strain rats.

A transcription initiation site for the hepatitis B virus X gene is directed by the promoter-binding protein

Recent studies have demonstrated the transacting function of the X gene product of hepatitis B virus. However, little information is available on the regulation of X gene expression. In this report, we first investigate a cellular factor regulating X gene transcription by DNA transfection, using the human hepatoma cell line HuH-7, which is permissive for HBV replication as well as X mRNA transcription. A sequence-specific cellular factor was found to bind to the promoter region upstream of the first ATG (nucleotide [nt] 1248) of the X open reading frame. DNase I footprinting analysis showed the binding sequence of this factor to be situated between nt 1097 and 1119, where an 8-bp palindrome structure resides. S1 nuclease analysis of X gene transcripts demonstrated the binding site to be adjacent to two major start sites (nt 1117 and 1125) of X mRNA. Second, we demonstrate that introduction of a mutation into the binding site gives rise to a loss of the binding with a concomitant shift of the transcription start site of X mRNA beyond the 8-bp palindrome structure, causing it to become more heterogeneous. Thus, the promoter-binding protein appears to be involved in directing the transcription initiation site of the X gene toward the downstream region of the X promoter when X protein is produced from X mRNA.

Cloning of a Ca(2+)-ATPase gene of Plasmodium falciparum and comparison with vertebrate Ca(2+)-ATPases

A Ca(2+)-ATPase gene was cloned from the genomic libraries of Plasmodium falciparum. From the deduced amino acid sequence of the gene, a 139 kDa protein with a total of 1228 amino acids was predicted. Sequence of a partial cDNA clone of the gene identified two introns near the 3′-end at the regions identical to the regions assumed for the Ca(2+)-ATPase gene of P. yoelii, a rodent malaria species. As compared with a variety of Ca(2+)-ATPases, the P. falciparum Ca(2+)-ATPase had the highest amino acid sequence homology (78%) to the P. yoelii Ca(2+)-ATPase, moderate homology (45-50%) to vertebrate sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPases (SERCAs), and lowest homology (20%) to a plasma membrane Ca(2+)-ATPase. The P. falciparum protein conserved sequences and residues that are important for the function and/or structure of the organellar type Ca(2+)-ATPase, such as high affinity Ca(2+)-binding sites, fluorescein isothiocyanate (FITC)-binding regions, and the phosphorylation site, but the protein did not contain calmodulin-binding regions that occur in the plasma membrane type Ca(2+)-ATPase. Thus we concluded the cloned gene was the organellar type Ca(2+)-ATPase of P. falciparum. In a region between the phosphorylation site and FITC-binding region, the P. falciparum protein was about 200 residues longer than the rabbit SERCA and lacked a sequence that binds to phospholamban, a protein that regulates the activity of the rabbit SERCA.(ABSTRACT TRUNCATED AT 250 WORDS)

Hybrid dysgenesis in natural populations of Drosophila melanogaster in Japan. III. The P-M system in and around Japan

The P-M system of hybrid dysgenesis in Drosophila melanogaster was investigated on the basis of gonadal dysgenesis, using 1,590 strains from 28 natural populations in Japan, and 20 populations from Southeast Asia, the Pacific area and Africa. Strong P strains were found sporadically in several populations in Japan. Few strong M strains were observed. Q strains were present at a high frequency in most populations. Thus, most populations in these areas were regarded as Q populations. The distribution of the P element and the evolution of P, Q and M populations are also discussed.

Functional domains of c-Myc involved in the commitment and differentiation of murine erythroleukemia cells

In the early event of the induction of mouse erythroleukemia (MEL) cell differentiation, c-myc mRNA levels show a drastic change. The elevated expression of a transfected c-myc gene inhibits the commitment and differentiation of MEL cell transformants. In the present work, we have introduced human c-myc mutants into MEL cells under the inducible promoter to define the functional domains of c-Myc involved in erythroid differentiation. The c-Myc domains necessary for commitment and differentiation are not co-localized; almost entire regions are required for inhibition of commitment, whereas domains II and IV that are essential for co-transforming activity with ras are required for inhibition of differentiation. Interestingly, mutants that delete domains for c-Myc dimerization motifs enhanced differentiation. These results suggest that c-Myc may regulate commitment and differentiation by interacting with proteins through different domains.

[Mechanism of hepatocarcinogenesis by hepatitis B virus]

The X gene product of hepatitis B virus (HBV) has a trans-activation function. The AP-1, AP-2, kappa B-like, and C/EBP-like sequences, and the 26-bp element in HBV enhancer were identified as X-responsive elements. Although the X protein possesses a transcriptional activation domain, it doesn't bind to the X-responsive elements. However, CREB/ATF-2 becomes able to bind to a CRE-related sequence in the 26-bp element once it complexes with X protein. In addition, X protein was shown to have amino acid sequences homologous to the essential domain of Kunitz-type serine protease inhibitors and directly interacted with the protease, tryptase TL2. Results suggest that X protein modulates the tryptase TL2 activity, which may be involved in the proteolytic cleavage of cellular transcription factors.

[Prognostic significance of auditory brainstem responses in full-term newborn infants with intracranial hemorrhages]

Auditory brainstem response (ABR) was recorded in 41 full-term newborn infants with intracranial hemorrhages (ICH; 10 infants with and 31 infants without neurological sequela) and the data were compared with those obtained in normal full-term newborn infants as controls. The wave-I peak latency was significantly prolonged in the non-sequela group than in the control group and in the sequela group than in the non-sequela group. The wave-III and wave-V peak latencies were significantly prolonged in the ICH group (sequela and non-sequela groups) than in the control group but did not significantly differ between the sequela and non-sequela group. The wave I-V interpeak latency did not significantly differ among the three groups. Among 10 infants in the sequela group, 9 had a V/I amplitude ratio (the amplitude of wave-I divided by the amplitude of wave- V) of less than 1.0. This suggests that the V/I amplitude ratio is of prognostic value in ICH infants.

Measurement of local directional pressures in the brain with mass

In order to understand the effects and the direction of pressure transmitted from a mass lesion through various brain structures, miniature strain gauges were inserted in different brain locations in eight anesthetized monkeys. Mass lesions were created by inflating a balloon in either of two locations--subcortical in four animals (Group I) and deep (lateral to the caudate nucleus) in the other four animals (Group II). Anterior-posterior directed pressures were thus measured from a gauge placed in the parietal lobe, and lateromedially directed pressures (LM-dPs) were measured from gauges in the temporal lobe and midbrain. Intracranial pressure, systemic mean arterial pressure, and cerebral blood flow were also monitored. After balloon inflation was begun, temporal changes in pressure were recorded from gauges as percentage increase or decrease from baseline measurements. In both groups, balloon inflation caused a gradual increase in the parietal lobe anterior-posterior directed pressure with a concomitant increase in intracranial pressure and a decrease in cerebral blood flow. The temporal lobe gauge in Group I recorded an initial negative followed by a positive LM-dP with further balloon inflation. In Group II, this gauge recorded a positive LM-dP throughout. The midbrain gauges in both groups recorded an initial positive followed by a negative LM-dP. This reversal in the direction of pressure in the midbrain occurred just before the supratentorial pressure reached a peak and was noted to be concurrent with a sudden rise in mean arterial pressure and a decline in cerebral blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of c-Myc on erythroid differentiation

In the early event of the induction of mouse erythroleukemia (MEL) cell differentiation, c-myc mRNA levels show a biphasic change. The elevated expression of a transfected c-myc gene inhibits the commitment and differentiation of MEL cell transformants. In the present work, we have introduced human c-myc mutants into MEL cells under the inducible promoter to define the functional domains of c-Myc involved in erythroid differentiation. The c-Myc domains necessary for commitment and differentiation are not colocalized; almost entire regions are required for inhibition of commitment, whereas domains II and IV that are essential for co-transforming activity with ras are required for inhibition of differentiation. Interestingly, mutants that delete domains for c-Myc dimerization motifs enhanced differentiation. Thus, c-Myc interferes with MEL cell differentiation by interacting with c-Myc partners and the induced protein(s) through dimerization domains. These results suggest that c-Myc may regulate commitment and differentiation by interacting with proteins through different domains.

OPC-13340, a new dihydropyridine calcium channel blocker attenuates rapid vascular smooth muscle cell growth in spontaneously hypertensive rats

We investigated the mechanism of the antimitotic effects of calcium channel blockers in vascular smooth muscle cells (VSMC) from spontaneously hypertensive rats (SHR). VSMC from SHR exhibited rapid proliferation through a quick transition from the G0/G1 to the DNA synthetic (S) phase and from the S to the G2/mitotic (M) phase, whereas the DNA synthetic rate itself was equal to that of Wistar-Kyoto rats (WKY). OPC-13340, a new dihydropyridine calcium channel blocker, dose-dependently decreased incorporation of [3H]thymidine into the DNA fragments in randomly cycling VSMC in SHR. Cell cycle analysis showed that the rapid transition from the S to the G2/M period was restored by OPC-13340 to the control level in WKY, whereas the quick transition from G0/G1 to S was unaffected. This antimitotic effect of OPC-13340 was reflected by attenuation of enhanced cellular protein synthesis during the G2/M period. Protein synthesis in the G0/G1 period was not influenced by OPC-13340. Thus, these data indicate that the calcium channel blocker OPC-13340 mitigates the enhanced proliferation observed in randomly cycling VSMC from SHR and that this effect is primarily due to normalization of the premature mitosis during the G2/M period.

Pharmacological aspects of arthritis induced by a muramyl dipeptide analogue in rats

Fourteen consecutive daily subcutaneous injections of 4 mg/kg of the muramyl dipeptide analogue MDP-Lys(L18) into rats caused arthritis characterized by swelling of the tarsal joint, increases in lymphocytes and monocytes in the peripheral blood, and elevated serum immunoglobulin G (IgG). The present study was performed to evaluate the effects of indomethacin, phenylbutazone, dexamethasone, D-penicillamine, aurothioglucose, cyclophosphamide and cyclosporin A on this arthritis. Administration of indomethacin, phenylbutazone or dexamethasone inhibited the development of the tarsal joint swelling, suggesting that prostaglandins may be involved in the pathogenesis of the arthritis. Cyclophosphamide reduced the arthritis, together with decreases in the lymphocyte count and the serum IgG level. Cyclosporin A worsened the arthritis in a dose-dependent manner and increased the neutrophil count without raising the serum IgG level, but inhibited the induction of adjuvant arthritis in rats with Mycobacterium bacilli. MDP-Lys(L18) may therefore induce arthritis differing in mechanism from adjuvant arthritis.

Pharmacokinetics of zonisamide; saturable distribution into human and rat erythrocytes and into rat brain

The distribution of zonisamide, a new antiepileptic drug, in erythrocytes and in brain was studied to clarify the factors influencing its distribution in epileptic patients. In both humans and rats, zonisamide was concentrated significantly in erythrocytes in a saturable manner. When the effective concentration of zonisamide in serum was compared with that in blood in nine refractory epileptic patients taking zonisamide chronically, the variation in effective serum concentration was significantly larger than that in blood concentration. In rats, the distribution in the brain also showed saturability. These results suggest that differences in saturable binding to various tissues may contribute to the wide variation that occurs in the effective serum concentration of zonisamide in epileptic patients and that monitoring of the blood concentration of zonisamide may provide useful information for treatment with this drug.

Three-headed outer arm dynein from Chlamydomonas that can functionally combine with outer-arm-missing axonemes

A procedure was developed for isolating Chlamydomonas outer-arm dynein that can functionally combine with the axoneme of an outer-arm-missing mutant, oda1. Previous studies showed that the outer-arm dynein of this organism, containing three heavy chains (alpha, beta, gamma), dissociates upon extraction with a high-salt-concentration buffer solution into an 18-S particle containing the alpha and beta heavy chains and a 12-S particle containing the gamma heavy chain. It was found, however, that the three heavy chains did not dissociate if the high-salt extract was centrifuged in the presence of Mg2+; the three chains constituted a single species (23-S dynein) sedimenting at about 23 S and displayed a three-headed bouquet configuration in electron micrographs. Furthermore, the 23-S dynein had the activity to bind to the axonemes of oda1 and increase the reactivated motility of detergent-extracted cell models; its addition increased the beat frequency from 28 Hz to 53 Hz, a frequency comparable to that of wild-type axoneme. The 18-S and 12-S dyneins, on the other hand, were unable to increase the motility of oda1 axonemes even when added together. The new protocol thus enables purification of outer-arm dynein that retains its functional activity. It will provide a useful experimental system with which to study the mechanism of outer-arm function.