Biomedical subjects

Qian Xu

Publications and source records attributed to Qian Xu.

At least 19 recordsLinked to original sources

PubMed2026

Auxin-induced ARF transcription factor degradation defines tissue boundaries.

How organs partition themselves into discrete domains with distinct functions is a fundamental question in biology. The gynoecium of flowering plants provides an excellent system to address this question. Here, we show that the boundary between the stigma and style at the gynoecium apex is established by the complementary distribution of the phytohormone auxin and the Auxin Response Factor (ARF), ETTIN (ETT). Mechanistically, auxin induces ETT protein destabilization via the ubiquitin-proteasome pathway. A short sequence motif within an intrinsically disordered region is required for this auxin-triggered degradation. Disruption of this motif leads to ectopic ETT accumulation at the gynoecium apex and consequently abolishes stigma-style boundary development. We further demonstrate that this previously unrecognized mode of auxin-induced ARF instability is evolutionarily conserved among ETT orthologs across angiosperms. In summary, this study reveals how graded auxin distribution affects ARF transcription factor activity, contributing to the establishment of the stigma-style boundary, ensuring correct gynoecium formation and reproductive success in flowering plants.

Indoleacetic Acids↗

PubMed2007

[Reversal effect of antisense RNA targeting human papillomavirus 16 (HPV16) E6E7 on malignancy of human cervical cancer cell line SiHa].

BACKGROUND & OBJECTIVE: The ubiquitinated degradation of p53 can be induced by human papillomavirus type 16 (HPV16) early gene 6 (E6); the phosphorylated inactivation of pRb can be induced by HPV16 E7. They are closely associated with the carcinogenesis and progression of cervical cancer. This study was to investigate the effects of HPV16 E6E7 antisense RNA on the expression of oncogene E6 and E7 and apoptosis of human cervical cancer cell line SiHa harboring HPV16 genome. METHODS: The antisense sequence of HPV16 E6E7 was cloned into eukaryotic expression vector pEGFP to prepare recombinant plasmid containing E6E7AS, which was transfected into SiHa cells. The mRNA and protein levels of E6 and E7 gene were detected by Western blot and reverse transcription-polymerase chain reaction (RT-PCR). Cell proliferation after transfection was evaluated by MTT assay. The apoptosis of transfected SiHa cells was assessed by flow cytometry (FCM) and confocal laser microscopy. RESULTS: After transfection of HPV16 E6E7 antisense RNA, the mRNA and protein levels of HPV16 E6 and E7 in SiHa cells were obviously decreased. The proliferation activity of SiHa/E6E7AS cells was significantly lower than that of SiHa/EGFP and SiHa cells (0.50+/-0.05 vs. 1.01+/-0.06, 1.28+/-0.06, P<0.05). The apoptosis rate was significantly higher in SiHa/E6E7AS cells than in SiHa/EGFP and SiHa cells [(59.3+/-11.3)% vs. (9.4+/-1.8)%, (2.1+/-0.4)%, P<0.05]. The apoptotic cells increased noticeably after transfection. CONCLUSION: Down-regulating HPV16 E6 and E7 with antisense RNA induces apoptosis in SiHa cells, and may be useful for HPV-associated malignancy gene therapy.

Apoptosis↗

PubMed2006

Expression of semaphorin 6D in gastric carcinoma and its significance.

AIM: To investigate the protein and mRNA expression of semaphorin 6D in gastric carcinoma and its significance. METHODS: The protein and mRNA expression of semaphorin 6D was detected by semi-quantitative reverse transcription PCR and Western blotting respectively in 30 cases of gastric carcinoma and normal gastric mucosa. RESULTS: The protein and mRNA expression of semaphorin 6D in gastric carcinoma was significantly higher than that in normal gastric mucosa (0.24 +/- 0.06 vs 0.19 +/- 0.07, 0.26 +/- 0.09 vs 0.20 +/- 0.10, P < 0.05). CONCLUSION: Semaphorin 6D may play an important role in the occurrence and development of gastric carcinoma, and is related to tumor angiogenesis.

Adult↗

PubMed2006

Saturation effect and forward-dominant second-harmonic generation in single-defect photonic crystals with dual localizations.

We study the forward-dominant output of second-harmonic generation (SHG) in single-defect and dual-localized photonic crystals within the saturation limit. We propose that an asymmetric structure can be used to improve the performance of the enhanced SHG. We get two empirical expressions for the total saturation SHG efficiency and the forward factor and provide a reasonable explanation. The theoretical results predict a nearly 100% conversion efficiency and a nearly 100% forward output. Our work is very valuable for designing nonlinear photonic devices. As a test, a practical asymmetrical structure is presented.

Journal Article↗

PubMed2006

Expression of Pin1 and Ki67 in cervical cancer and their significance.

In order to investigate the expression levels of Pin1 mRNA and protein in cervical cancer and its association with Ki67 and their clinical significance, amplification of Pin1 gene was examined by RT-PCR, and the expression of both Pin1 and Ki67 protein was detected by immunohistochemistry in cervical cancer tissues. It was shown that the expression levels of Pin1 were higher in cervical cancer than in normal cervical tissues (P < 0.05). The expression of Pin1 protein was increased progressively along with the disease process from normal cervix to CIN and to cervical cancer (P < 0.05). No significant difference in the Pin1 expression was found between disease stages (FIGO), pathological grades or pelvic lymph node metastasis status (P > 0.05). The expression of Pin1 was significantly higher in adenocarcinoma than in squamous carcinoma of the uterine cervix (P < 0.05). In cervical cancer, the overexpression of Pin1 was positively correlated with that of Ki67 (P < 0.05). These results suggested that the overexpression of Pin1 was closely related with cancer cell proliferation or progression of cervical cancer and contributed to oncogenesis. Pin1 may serve as a potential marker for cervical cancer diagnosis.

Biomarkers, Tumor↗

PubMed2006

Central corneal thickness in adult Chinese.

The central corneal thickness (CCT) in age 48 years or less of Chinese was characterized and its relationship with gender, age, refraction and intraocular pressure (IOP) was investigated. Right eyes of 1669 participants were included in this study (880 men, 52.7% and 789 women, 47.3%). Mean age of the samples was 23.8 +/- 5.9 years. After the examination of corneal topography and refraction, Goldman applanation tonometry was carried out by one physician. Tonometric values were the mean of three consecutive readings. Subsequently, another physician carried out ultrasonic pachymetry with the DGH 2000 AP ultrasonic pachymeter. Six measurements were made at the center of the cornea of each eye. The mean value was used for analysis. The results showed that mean CCT of male participants was 551.33 +/- 34.62 microm, 5.79 microm more than that of female participants. Linear regression analyses revealed that CCT was negatively related with age only in female and no association was found between refractive status and CCT. IOP was positively related to CCT, and there was a difference in IOP of 1.5 mmHg (1 mmHg = 0.133 kPa) per 100 microm difference in CCT. Ocular hypertension group was prone to have thicker cornea than average. The results indicated that in adult Chinese CCT tended to decrease with aging in female only. IOP measured by Goldmann tonometry was positively related with CCT so that CCT should be measured along with IOP.

Adolescent↗

PubMed2006

Layered Wyner-Ziv video coding.

Following recent theoretical works on successive Wyner-Ziv coding (WZC), we propose a practical layered Wyner-Ziv video coder using the DCT, nested scalar quantization, and irregular LDPC code based Slepian-Wolf coding (or lossless source coding with side information at the decoder). Our main novelty is to use the base layer of a standard scalable video coder (e.g., MPEG-4/H.26L FGS or H.263+) as the decoder side information and perform layered WZC for quality enhancement. Similar to FGS coding, there is no performance difference between layered and monolithic WZC when the enhancement bitstream is generated in our proposed coder. Using an H.26L coded version as the base layer, experiments indicate that WZC gives slightly worse performance than FGS coding when the channel (for both the base and enhancement layers) is noiseless. However, when the channel is noisy, extensive simulations of video transmission over wireless networks conforming to the CDMA2000 1X standard show that H.26L base layer coding plus Wyner-Ziv enhancement layer coding are more robust against channel errors than H.26L FGS coding. These results demonstrate that layered Wyner-Ziv video coding is a promising new technique for video streaming over wireless networks.

Algorithms↗

PubMed2006

Type IV pili function upstream of the Dif chemotaxis pathway in Myxococcus xanthus EPS regulation.

The developmental bacterium Myxococcus xanthus utilizes gliding motility to aggregate during the formation of multicellular fruiting bodies. The social (S) component of M. xanthus gliding motility requires at least two extracellular surface structures, type IV pili (Tfp) and the fibril polysaccharide or exopolysaccharide (EPS). Retraction of Tfp is proposed to power S motility and EPS from neighbouring cells is suggested to provide an anchor and trigger for Tfp retraction. The production of EPS in M. xanthus is regulated in part by the Dif chemosensory pathway; however, the input signal for the Dif pathway in EPS regulation remains to be uncovered. Using a genetic approach combined with quantitative and qualitative analysis, we demonstrate here that Tfp function upstream of the Dif proteins in regulating EPS production. The requirement of Tfp for the production of EPS was verified using various classes of Tfp mutants. Construction and examination of double and triple mutants indicated that mutations in dif are epistatic to those in pil. Furthermore, extracellular complementation between various Tfp and dif mutants suggests that Tfp, instead of being signals, may constitute the sensor or part of the sensor responsible for mediating signal input into the Dif pathway. We propose that S motility involves a regulatory loop in which EPS triggers Tfp retraction and Tfp provide proximity signals to the Dif pathway to modulate EPS production.

Bacterial Proteins↗

PubMed2006

Confidence intervals for the true classification error conditioned on the estimated error.

Bias and variance for small-sample error estimation are typically posed in terms of statistics for the distributions of the true and estimated errors. On the other hand, a salient practical issue asks, given an error estimate, what can be said about the true error? This question relates to the joint distribution of the true and estimated errors, specifically, the conditional expectation of the true error given the error estimate. A critical issue is that of confidence bounds for the true error given the estimate. We consider the joint distribution of the true error and the estimated error, assuming a random feature-label distribution. From it, we derive the marginal distributions, the conditional expectation of the estimated error given the true error, the conditional expectation of the true error given the estimated error, the conditional variance of the true error given the estimated error, and the 95% upper confidence bound for the true error given the estimated error. Numerous classification and estimation rules are considered across a number of models. Massive simulation is used for continuous models and analytic results are derived for discrete classification. We also consider a breast-cancer study to illustrate how the theory might be applied in practice. Although specific results depend on the classification rule, error-estimation rule, and model, some general trends are seen: (I) if the true error is small (large), then the conditional estimated error is generally high (low)-biased; (II) the conditional expected true error tends to be larger (smaller) than the estimated error for small (large) estimated errors; and (III) the confidence bounds tend to be well above the estimated error for low error estimates, becoming much less so for large estimates.

Algorithms↗

PubMed2006

[Expression and clinical significance of Pin1 and Cyclin D1 in cervical cancer cell lines and cervical epithelial tissues].

BACKGROUND & OBJECTIVE: Peptidyl-prolyl cis/trans isomerase Pin1 is prevalently overexpressed in human cancers. Up-regulation of Pin1 elevates the expression of Cyclin D1, and plays an important role in tumorigenesis and tumor progression. This study was to investigate the expression and clinical significance of Pin1 and Cyclin D1 in cervical cancer cell lines and cervical epithelial tissues. METHODS: The expression of Pin1 and Cyclin D1 in cervical cancer cell lines HeLa, SiHa, C33a and Caski were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Their expression in 88 samples of cervical tissues, including 10 samples of normal cervix, 21 samples of cervical intraepithelial neoplasia (CIN), and 57 samples of invasive cervical cancer, were detected by immunohistochemistry. RESULTS: The mRNA and protein levels of Pin1 were significantly higher in HeLa, SiHa, C33a, and Caski cells than in normal cervical epithelial tissues (P<0.05). The expression of Pin1 increased progressively along with the disease process from normal cervix to CIN, and to invasive cervical cancer (0%, 47.62%, 64.91%, P<0.05). Pin1 expression had no relation to disease stage (FIGO), pathologic grade, and pelvic lymph node metastasis status (P>0.05). The positive rate of Pin1 was significantly higher in cervical adenocarcinoma than in cervical squamous cell carcinoma (100% vs. 60.0%, P<0.05). In cervical cancer tissues, the overexpression of Pin1 was positively correlated to that of Cyclin D1 (P<0.05). CONCLUSIONS: Pin1 is overexpressed in HeLa, SiHa, C33a and Caski cell lines as well as in cervical cancer tissues. The overexpression of Pin1 is closely related to Cyclin D1 expression in cervical cancer. The aberrant expression of Pin1 and Cyclin D1 might contribute to tumorigenesis of cervical cancer.

Adenocarcinoma↗

PubMed2006

[Effect of perfusion CT scan on hepatic hemodynamic changes in rats with liver micrometastases].

BACKGROUND & OBJECTIVE: Hepatic metastases are common for patients with malignant tumors, especially for the gastrointestinal malignancies. Early diagnosis confers better prognosis. This study was designed to investigate the hepatic hemodynamic changes by multi-slice helical perfusion CT in rats with liver micrometastatases of Walker-256 tumor cells. METHODS: Liver micrometastatases were produced in 22 SD rats by injecting 2 x 10(7) Walker-256 cells into the spleens. The ten experimental control rats were injected with normal saline solution. Ten rats were randomized into empty self control group from the experimental group before injecting tumor cells, which were studied by CT perfusion technique before being injected tumor cells. The time-density curves of the aorta, portal vein, and liver were used to calculate liver perfusion parameters by gradient method designed for the dual blood supply. These liver perfusion parameters were hepatic arterial perfusion (HAP), portal vein perfusion (PVP), hepatic perfusion index (HPI) and total hepatic blood flow. All the parameters were compared between the groups. H&E staining method was used to confirm the micrometastases pathologically. RESULTS: In the experimental group, 19 rats were found with micrometastases, of which the diameter was 0.5 mm to 6.6 mm. HAP was (97.67+/-31.42) ml x min(-1) x (100 ml) (-1) in metastasis group, and (43.35+/-17.39)ml x min(-1) x (100 ml) (-1) in control group, and (40.77+/-18.91) ml x min(-1) x (100 ml) (-1) in empty self control group. PVP was (295.49+/-61.85) ml x min(-1) x (100 ml) (-1) in metastasis group, and (385.7+/-71.25) ml x min(-1) x (100 ml) (-1) in control group, and (362.73+/-78.56) ml x min(-1) x (100 ml) (-1) in empty self control group, It was found that the HAP was higher in the rats with micrometastases than in those of the empty control group and also those of control group (F=47.84, P<0.000,1). While the PVP was lower in the rats with micrometastases than in those of the two control groups (F=14.10, P<0.000,1). For the total hepatic blood flow, no significant difference was found among the three groups (F=1.39, P=0.255). CONCLUSION: Higher HAP and lower PVP was noted in the rats with micrometastases. Perfusion CT technique can be used to evaluate the hepatic hemodynamic changes and thus has a potential clinical value for early diagnosis of liver micrometastases.

Animals↗

PubMed2006

[Short hairpin RNA silences Pin1 and affects proliferation and apoptosis in HeLa cell line].

OBJECTIVE: To study the effect of short hairpin RNA (shRNA) on the expression of Pin1 mRNA and protein and its influence on the proliferation and apoptosis in HeLa cell lines. METHODS: The recombinant plasmid pSIREN-Pin1 expressing Pin1-targeted shRNA was constructed and then transfected into cervical cancer cell lines by lipofectamine (HeLa/p-shRNA), the control vector pSIREN-Con (HeLa/p-Con) and culture media (HeLa) as control, respectively. The Pin1 mRNA and protein expression were detected by RT-PCR and immunoblotting. The proliferation of cells after transfection was detected by methyl thiazolyl tetrazolium (MTT) and colony formation in soft agar. Flow cytometry (FCM) was used to test the apoptosis of cells marked with fluorescein isothiocyanate (FITC)-annexin V. RESULTS: After transfected with pSIREN-Pin1 for 48 h, the expression of Pin1 mRNA and protein in HeLa cells were 0.19 +/- 0.05 and 0.33 +/- 0.14 respectively. Compared with HeLa/p-Con cells (0.84 +/- 0.16, 0.79 +/- 0.17) and HeLa cells (0.89 +/- 0.11, 0.81 +/- 0.15), the difference was significant respectively (P < 0.05). The proliferation was suppressed significantly in HeLa/p-shRNA cells. The colony ratios are as follows: HeLa/p-shRNA, (12 +/- 3)%; HeLa/p-Con, (20 +/- 5)%; HeLa, (24 +/- 4)% (P < 0.05). The apoptosis ratio was (24.3 +/- 5.7)% in HeLa/p-shRNA cells. It was significantly higher than that in HeLa/p-Con cells (5.0 +/- 1.4)% and HeLa cells (1.8 +/- 0.4)% (P < 0.05). CONCLUSIONS: RNA interference through Pin1-targeted shRNA can effectively inhibit the expression of target gene, and might be potentially useful in gene therapy of Pin1 related cervical cancers. Silencing Pin1 gene can suppress the proliferation and promote the apoptosis in HeLa cells.

Apoptosis↗

PubMed2006

Pin1 contributes to cervical tumorigenesis by regulating cyclin D1 expression.

The prolyl isomerase Pin1, which specifically catalyzes conformational changes in certain proline-directed phosphorylation sites, is thought to be a critical catalyst for multiple oncogenic pathways. However, little is known about the role of Pin1 in human cervical cancer. Our previous study showed that Pin1 was overexpressed in cervical cancer tissues as well as cell lines. In this study, whether Pin1 is involved in cervical oncogenesis by regulating cyclin D1 was explored and the potential of Pin1-targeted gene silencing in inhibiting cellular growth and tumorigenicity in cervical cancer was investigated. A Pin1-directed shRNA and a sense Pin1 plasmid were constructed, and then the effects of the shRNA and the sense plasmid on HeLa cells were evaluated. The results showed that Pin1 directly regulated cyclin D1 levels. In addition, silencing Pin1 with RNAi significantly reduced cancer cell proliferation, colony formation, and strongly enhanced the apoptosis of HeLa cells. It is suggested that Pin1 may contribute to cervical tumorigenesis by regulating cyclin D1 expression and Pin1 may serve as a promising molecular target for diagnostics and therapeutics in cervical cancer.

Apoptosis↗

PubMed2006

Regulation of DNA methylation on the expression of the FHIT gene contributes to cervical carcinoma cell tumorigenesis.

The purpose of this study was to determine the effect of the FHIT gene on tumorigenesis of cervical cancer. RT-PCR and MTT were used to detect the expression of FHIT and cell proliferation respectively. Flow cytometry was used to test cell cycle and cell apoptosis. The expression of FHIT was not induced at all four cervical cancer cells treated with demethylating agent 5-aza-2'-deoxycytidine (5-Aza-CdR). However, a constant level of FHIT expression was detected in the human umbilical vein endothelial cell before and after 5-aza-dC treatment. The proliferation of all four cervical cancer cells was inhibited evidently when treated with 5-aza-dC and the inhibiting rate of cell growth along with the increasing concentration of 5-aza-dC. There was no obvious inhibiting effect on the growth of the human umbilical vein endothelial cell treated with 5-aza-dC. An increasing G1 phase and high apoptosis rate were detected in all four cervical cancer cells. However, a negligible change was seen in the human umbilical vein endothelial cell. These results suggest that aberrant methylation of the FHIT gene might be a key mechanism for silenced FHIT gene, which could be reactivated and whose tumor suppressing function could be restored by demethylating agent treatment.

Acid Anhydride Hydrolases↗

PubMed2005

Effects of human papillomavirus type 16 E7 protein on the growth of cervical carcinoma cells and immuno-escape through the TGF-beta1 signaling pathway.

OBJECTIVE: E7 is regarded as one of the main oncoproteins of high-risk human papillomaviruses (HPVs). It may affect the transforming growth factor beta 1 (TGF-beta1) signaling pathway. In this study, the relationship between HPV-16 infection and the functions of three critical factors of the TGF-beta1/Smads pathway was explored to assess the possible role of E7 in the development of cervical cancer. METHODS: The expression of E7, TGF-beta1, TbetaR-II and Smad4 was detected by immunohistochemistry in paraffin-embedded cervical samples, and by RT-PCR and Western blotting in cervical cancer cell lines. The effect of TGF-beta1 on the growth of cervical cancer cells were tested by methyl thiazolyl tetrazolium (MTT), and the effects of HPV-16 E7 protein on normal and malignant cervical cells were investigated by flow cytometry. RESULTS: During the progression from benign to malignant lesions, the expression levels of TGF-beta1 and Smad4 increased significantly in cervical carcinoma tissues. The expression of TGF-beta1 was positively correlated with E7 expression. In vitro experiments showed that TGF-beta1 could not inhibit the proliferation of several cervical carcinoma cell lines in long-term regulation, but could inhibit immunologic reactions of peripheral blood mononuclear cells (PBMCs). Blocking E7 expression could lower the expression level of TGF-beta1 and induce cells to enter apoptosis. CONCLUSIONS: Our data indicate that HPV-16 E7 protein plays an important role during the development of cervical cancer by immuno-inhibition and stimulation of tumor cell proliferation through the TGF-beta1/Smads signaling pathway.

Cell Growth Processes↗

PubMed2005

Myosin VIIB from Drosophila is a high duty ratio motor.

Myosin VII is an unconventional myosin widely expressed in organisms ranging from amoebae to mammals that has been shown to play vital roles in cell adhesion and phagocytosis. Here we present the first study of the mechanism of action of a myosin VII isoform. We have expressed a truncated single-headed Drosophila myosin VIIB construct in the baculovirus-Sf9 system that bound calmodulin light chains. By using steady-state and transient kinetic methods, we showed that myosin VIIB exhibits a fast release of phosphate and a slower, rate-limiting ADP release from actomyosin. As a result, myosin VIIB will be predominantly strongly bound to actin during steady-state ATP hydrolysis (its duty ratio will be at least 80%). This kinetic pattern is in many respects similar to that of the single-molecule vesicle transporters myosin V and VI. The enzymatic properties of myosin VIIB provide a kinetic basis for processivity upon possible dimerization via the C-terminal domains of the heavy chain. Our experiments also revealed conformational heterogeneity of the actomyosin VIIB complex in the absence of nucleotide.

Actins↗

PubMed2005

Value and feasibility of HPV DNA test in cervical scraping smears.

To investigate the reliability and feasibility of human papillomavirus (HPV) DNA test in cervical scraping smears with polymerase chain reaction (PCR), 131 cases of cervical scraping specimens were collected, and the positive rates and accuracy of HPV infection were determined in normal subjects and cervical cancer patients. GP5+/GP6+ and E7 primer pairs designed for detecting HPV L1 and HPV type 16 E7 were tested in this study. Our results showed that positive rates of HPV DNA in normal population and cervical cancer patients were 32.99% and 73.53% respectively and there was significant difference between them (P < 0.001). In normal subjects, detection rates of HPV DNA with GP5+/GP6+ and E7 primer pairs were 27.84% and 16.49% respectively, with statistically significant difference between them (P > 0.05). However the detection rates in cervical cancer patients were 38.24% and 67.65% for the two markers, with a significant difference found between them (P < 0.05). It is concluded that HPV DNA test with PCR for cervical scraping smears was feasible. GP5+/GP6+ primer pairs may be a useful probe to screen HPV infection in normal population, but they are not sensitive enough in cervical cancer patients. It is suggested that high risk type HPV DNA test was very useful in population with high risk of cervical cancer.

Capsid Proteins↗

PubMed2005

The Dif chemosensory pathway is directly involved in phosphatidylethanolamine sensory transduction in Myxococcus xanthus.

Myxococcus xanthus cells glide on solid surfaces and are chemotactically stimulated by certain phosphatidylethanolamine species. The dif gene cluster consists of six genes, difABCDEG, five of which encode proteins homologous to known chemotaxis proteins. DifA and DifE are required for the biosynthesis of fibrils, an extracellular matrix comprised of polysaccharide and protein. Chemotactic stimulation by 1,2-O-Bis[11-(Z)-hexadecenoyl]-sn-glycero-3-phosphatidylethanolamine (16:1 PE) and dilauroyl PE (12:0 PE) requires fibrils. Although previous work has shown that difA and difE mutants are not stimulated by 12:0 PE, these results do not distinguish between a dependence on fibrils or a direct role in chemosensory transduction. Here we provide evidence that the Dif chemosensory pathway directly mediates PE sensory transduction. First, stimulation by and adaptation to 16:1 PE requires all of the dif genes, including difBDG, which are not essential for fibril biogenesis. Second, a specific residue within the first putative methylation domain of DifA is required for stimulation by 16:1 PE but not fibril biogenesis. Transmembrane signalling through a chimeric NarX-DifA chemoreceptor is required for fibril formation but not for stimulation by or adaptation to 16:1 PE. Third, difD and difE are required for stimulation by dioleoyl PE (18:1 PE) although the response does not require fibrils. Taken together these results argue that the Dif pathway mediates both matrix formation and lipid chemotaxis.

Chemotaxis↗