Search PubMed⌕ Search

Biomedical subjects

Yueqiang Zhang

Publications and source records attributed to Yueqiang Zhang.

3 recordsLinked to original sources

Comparative transcriptomic and physiological analyses uncover key regulatory pathways associated with drought tolerance in wheat.

Drought severely limits wheat yield, yet its molecular basis remains incompletely understood. We compared a drought-tolerant line (A25) and a drought-sensitive line (A8) under water deficit across three developmental stages using physiological assays and transcriptomics. A25 exhibited stronger osmotic adjustment and antioxidant defense, with higher proline accumulation and enhanced activities of ascorbate peroxidase, catalase, and other ROS-scavenging enzymes. RNA-seq revealed distinct drought-responsive expression patterns, with differentially expressed genes enriched in MAPK signaling and ABA-dependent pathways. ABA-responsive genes were more abundant and strongly induced in A25, suggesting enhanced ABA signal transduction as a key mechanism. Weighted gene co-expression network analysis identified a drought-associated purple module positively correlated with physiological resistance, from which six hub genes (MAPKKK17, Avr9/Cf-9, RPPL1, RGA1, UBC28, AGPs5) were highlighted as potential regulators. Collectively, coordinated activation of ABA signaling and MAPK cascades, mediated by these hub genes, underlies the robust drought tolerance of A25, providing promising molecular targets for wheat breeding and improvement.

Triticum↗

Trans-activation of EphA4 and FGF receptors mediated by direct interactions between their cytoplasmic domains.

A yeast two-hybrid analysis has shown that the juxtamembrane region of FGF receptor 3 (FGFR3) interacts with the cytoplasmic domain of EphA4, which is a member of the largest family of receptor tyrosine kinases. Complex formation between the two receptors was shown to be mediated by direct interactions between the juxtamembrane domain of FGFR1, FGFR2, FGFR3, or FGFR4 and the N-terminal portion of the tyrosine kinase domain of EphA4. Activation of FGFR1 in transfected cells resulted in tyrosine phosphorylation of a kinase-negative EphA4 mutant and activation of EphA4 led to tyrosine phosphorylation of a kinase-negative FGFR1 mutant. Moreover, both receptors stimulate tyrosine phosphorylation of the docking protein FRS2alpha and induce mitogen-activated protein kinase stimulation with a time course and intensity that depends on the ligand that is applied. We also demonstrate that FGF-receptor-mediated mitogen-activated protein kinase stimulation is potentiated in cells costimulated with ephrin-A1. The direct interaction between EphA4 and FGFRs and the potentiation of FGF response that is induced by ephrin-A1 stimulation may modulate the biological responses that are mediated by these receptor families in cells or tissues in which the two receptors are coexpressed.

Antibodies, Monoclonal↗

Fibroblast growth factor 23 reduces expression of type IIa Na+/Pi co-transporter by signaling through a receptor functionally distinct from the known FGFRs in opossum kidney cells.

Fibroblast growth factor (FGF) 23 is an important phosphaturic factor that inhibits inorganic phosphate (Pi) reabsorption from the renal proximal tubule. Its overproduction and proteolysis-resistant mutation such as R179Q cause tumor-induced osteomalacia and autosomal dominant hypophosphatemic rickets, respectively. To clarify the signaling mechanisms of FGF23 that mediate the reduction of Pi reabsorption, we inhibited the function of the known FGFRs in opossum kidney (OK-E) cells by expressing a dominant-negative (DN) form of FGFR. OK-E cells, which represent the renal proximal tubular cells, expressed all four known FGFRs. FGF23(R179Q) bound to and activated FGFR2, a prominent FGFR expressed in OK-E cells. The activated receptor transmitted a signal to increase the expression of type IIa Na(+)/Pi co-transporter and the Pi uptake. Expression of FGFR2(DN), which suppresses the major FGFR-mediated signal through the FRS2alpha-ERK pathway, reversed the function of FGF23(R179Q). When FGF23(R179Q) was applied to the basolateral side of polarized OK-E cells, regardless of the FGFR2(DN) expression, the apical Pi uptake decreased significantly. The apical application of FGF23(R179Q) in the polarized cells did not show such decrease but increase. The exogenously expressed FGFR2 was detectable only at the apical membrane. These results suggest that an FGF23 receptor, which is functionally distinct from the known FGFRs, is expressed at the basolateral membrane of OK-E cells.

Animals↗