Dynein Light Intermediate Chains Exhibit Different Arginine Methylation Patterns.

BACKGROUND: The motor protein dynein is integral to retrograde transport along microtubules and interacts with numerous cargoes through the recruitment of cargo-specific adaptor proteins. This interaction is mediated by dynein light intermediate chain subunits LIC1 (DYNC1LI1) and LIC2 (DYNC1LI2), which govern the adaptor binding and are present in distinct dynein complexes with overlapping and unique functions. METHODS: Using bioinformatics, we analyzed the C-terminal domains (CTDs) of LIC1 and LIC2, revealing similar structural features but diverse post-translational modifications (PTMs). The methylation status of LIC2 and the proteins involved in this modification were examined through immunoprecipitation and immunoblotting analyses. The specific methylation sites on LIC2 were identified through a site-directed mutagenesis analysis, contributing to a deeper understanding of the regulatory mechanisms of the dynein complex. RESULTS: We found that LIC2 is specifically methylated at the arginine 397 residue, a reaction that is catalyzed by protein arginine methyltransferase 1 (PRMT1). CONCLUSIONS: The distinct PTMs of the LIC subunits offer a versatile mechanism for dynein to transport diverse cargoes efficiently. Understanding how these PTMs influence the functions of LIC2, and how they differ from LIC1, is crucial for elucidating the role of dynein-related transport pathways in a range of diseases. The discovery of the arginine 397 methylation site on LIC2 enhances our insight into the regulatory PTMs of dynein functions.

[Feasibility study of arterial pressure measurement by snuff pot artery puncture].

OBJECTIVE: To explore the feasibility of snuff pot arterial pressure measurement for patients undergoing routine elective surgery during anesthesia. METHODS: A prospective randomized controlled trial was conducted. Patients undergoing elective surgery admitted to the Handan Hospital of Traditional Chinese Medicine from June 1, 2020 to June 1, 2022 were enrolled. Patients who needed arterial pressure measurement for hemodynamic monitoring were randomly divided into routine radial artery puncture group and snuff pot artery puncture group with their informed consent. The patients in the routine radial artery puncture group were placed a catheter at the styloid process of the patient's radius to measure pressure. In the snuff pot artery puncture group, the snuff pot artery, that was, the radial fossa on the back of the hand (snuff box), was selected to conduct the snuff pot artery puncture and tube placement for pressure measurement. The indwelling time of arterial puncture catheter, arterial blood pressure, and complications of puncture catheterization of patients in the two groups were observed. Multivariate Logistic regression analysis was used to screen the relevant factors that affect the outcome of arterial catheterization. RESULTS: Finally, a total of 252 patients were enrolled, of which 130 patients received routine radial artery puncture and 122 patients received snuff pot artery puncture. There was no statistically significant difference in general information such as gender, age, body mass index (BMI), and surgical type of patients between the two groups. There was no significant difference in the indwelling time of artery puncture catheter between the routine radial artery puncture group and the snuff pot artery puncture group (minutes: 3.4±0.3 vs. 3.6±0.3, P > 0.05). The systolic blood pressure (SBP) and the diastolic blood pressure (DBP) measured in the snuff pot artery puncture group were significantly higher than those in the conventional radial artery puncture group [SBP (mmHg, 1 mmHg ≈ 0.133 kPa): 162.3±14.3 vs. 156.6±12.5, DBP (mmHg): 85.3±12.6 vs. 82.9±11.3, both P < 0.05]. There was no statistically significant difference in the incidence of complications such as arterial spasm, arterial occlusion, and pseudoaneurysm formation between the two groups. However, the incidence of hematoma formation in the snuff pot artery puncture group was significantly lower than that in the conventional radial artery puncture group (2.5% vs. 4.6%, P < 0.05). Based on the difficulty of arterial puncture, multivariate Logistic regression analysis showed that gender [odds ratio (OR) = 0.643, 95% confidence interval (95%CI) was 0.525-0.967], age (OR = 2.481, 95%CI was 1.442-4.268) and BMI (OR = 0.786, 95%CI was 0.570-0.825) were related factors that affect the outcome of arterial catheterization during anesthesia in patients undergoing elective surgery (all P < 0.05). CONCLUSIONS: Catheterization through the snuff pot artery can be a new and feasible alternative to conventional arterial pressure measurement.

Identification of iron-responsive genes in Proteus vulgaris.

Iron is essential for almost all bacteria, and iron homeostasis is precisely controlled by the ferric uptake regulator (Fur). The Fur regulons have been well characterized in some model bacteria, yet little is known in the common opportunistic pathogen Proteus vulgaris. In this study, Fur regulon and iron-responsive genes in P. vulgaris were mainly defined by in silico and proteomic analyses. The results showed that about 250 potential Fur-regulated operons including 14 transcriptional factors were predicted, while 559 proteins exhibited differential expression in response to iron deficiency, not all being directly regulated by Fur, such as transcriptional factors lexA, recA, narL, and arcA. Collectively, these results demonstrated that Fur functioned as a global regulatory protein to repress or activate expression of a large repertoire of genes in P. vulgaris; besides, not all the iron-responsive genes were directly regulated by Fur, whereas indirectly regulated through other mechanisms such as additional transcriptional regulatory proteins.