scholarly journals MAPKs Influence Pollen Tube Growth by Controlling the Formation of Phosphatidylinositol 4,5-Bisphosphate in an Apical Plasma Membrane Domain

2017 ◽  
Vol 29 (12) ◽  
pp. 3030-3050 ◽  
Author(s):  
Franziska Hempel ◽  
Irene Stenzel ◽  
Mareike Heilmann ◽  
Praveen Krishnamoorthy ◽  
Wilhelm Menzel ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Tube Growth ◽  
Apical Plasma Membrane ◽  
Membrane Domain ◽  
Plasma Membrane Domain

scholarly journals Signalling Pinpointed to the Tip: The Complex Regulatory Network That Allows Pollen Tube Growth

Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1098 ◽  
Author(s):  
Patricia Scholz ◽  
Jannis Anstatt ◽  
Hannah Elisa Krawczyk ◽  
Till Ischebeck
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Tube Growth ◽  
Complex Life Cycle ◽  
Apical Plasma Membrane ◽  
Interaction Point ◽  
Directional Growth ◽  
Exocyst Complex ◽  
Open Questions ◽  
The Individual

Plants display a complex life cycle, alternating between haploid and diploid generations. During fertilisation, the haploid sperm cells are delivered to the female gametophyte by pollen tubes, specialised structures elongating by tip growth, which is based on an equilibrium between cell wall-reinforcing processes and turgor-driven expansion. One important factor of this equilibrium is the rate of pectin secretion mediated and regulated by factors including the exocyst complex and small G proteins. Critically important are also non-proteinaceous molecules comprising protons, calcium ions, reactive oxygen species (ROS), and signalling lipids. Among the latter, phosphatidylinositol 4,5-bisphosphate and the kinases involved in its formation have been assigned important functions. The negatively charged headgroup of this lipid serves as an interaction point at the apical plasma membrane for partners such as the exocyst complex, thereby polarising the cell and its secretion processes. Another important signalling lipid is phosphatidic acid (PA), that can either be formed by the combination of phospholipases C and diacylglycerol kinases or by phospholipases D. It further fine-tunes pollen tube growth, for example by regulating ROS formation. How the individual signalling cues are intertwined or how external guidance cues are integrated to facilitate directional growth remain open questions.

scholarly journals Expression, Distribution, and Activity of Na+,K+-ATPase in Normal and Cholestatic Rat Liver

1998 ◽  
Vol 46 (3) ◽  
pp. 405-410 ◽  
Author(s):  
Lukas Landmann ◽  
Sabine Angermüller ◽  
Christoph Rahner ◽  
Bruno Stieger
Keyword(s):  
Enzyme Activity ◽  
Plasma Membrane ◽  
Driving Force ◽  
Bile Secretion ◽  
Transport Systems ◽  
Apical Plasma Membrane ◽  
Membrane Domain ◽  
Expression Domain ◽  
Duct Ligation ◽  
Plasma Membrane Domain

Hepatocellular Na+,K+-ATPase is an important driving force for bile secretion and has been localized to the basolateral plasma membrane domain. Cholestasis or impaired bile flow is known to modulate the expression, domain specificity, and activity of various transport systems involved in bile secretion. This study examined Na+,K+-ATPase after ethinylestradiol (EE) treatment and after bile duct ligation (BDL), two rat models of cholestasis. It applied quantitative immunoblotting, biochemical and cytochemical determination of enzyme activity, and immunocytochemistry to the same livers. The data showed a good correlation among the results of the different methods. Neither EE nor BDL induced alterations in the subcellular distribution of Na+,K+-ATPase, which was found in the basolateral but not in the canalicular (apical) plasma membrane domain. Protein expression and enzyme activity showed a small (~10%) decrease after EE treatment and a similar increase after BDL. These modest changes could not be detected by immunofluorescence, immuno EM, or cytochemistry. The data, therefore, demonstrate that Na+,K+-ATPase is only slightly affected by EE and BDL. They suggest that other components of the bile secretory apparatus that take effect downstream of the primary basolateral driving force may play a more prominent role in the pathogenesis of cholestasis.

scholarly journals Plasma membrane H + ‐ATPases‐mediated cytosolic proton gradient regulates pollen tube growth

2020 ◽  
Vol 62 (12) ◽  
pp. 1817-1822 ◽  
Author(s):  
Wei Chen ◽  
Peng‐Fei Jia ◽  
Wei‐Cai Yang ◽  
Hong‐Ju Li
Keyword(s):  
Plasma Membrane ◽  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Proton Gradient ◽  
Tube Growth

scholarly journals Plasma membrane H+-ATPases sustain pollen tube growth and fertilization

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Robert D. Hoffmann ◽  
Maria Teresa Portes ◽  
Lene Irene Olsen ◽  
Daniel Santa Cruz Damineli ◽  
Maki Hayashi ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Tube Growth
Sign in / Sign up

Export Citation Format

Share Document