We investigated the molecular basis and physiological implications of anion transport during pollen tube ( Patch‐clamp whole‐cell configuration analysis of pollen grain protoplasts revealed three subpopulations of anionic currents differentially regulated by cytoplasmic calcium ([Ca2+]cyt). We investigated the pollen‐expressed proteins Our data show that
Ari Helenius launched the field of enveloped virus fusion in endosomes with a seminal paper in the
- NSF-PAR ID:
- 10247855
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Traffic
- Volume:
- 17
- Issue:
- 6
- ISSN:
- 1398-9219
- Page Range / eLocation ID:
- p. 593-614
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Summary PT ) growth inArabidopsis thaliana (Col‐0).At SLAH 3,At ALMT 12,At TMEM 16 andAt CCC as the putative anion transporters responsible for these currents.At CCC ‐GFP was observed at the shank andAt SLAH 3‐GFP at the tip and shank of thePT plasma membrane. Both are likely to carry the majority of anion current at negative potentials, as extracellular anionic fluxes measured at the tip ofPT s with an anion vibrating probe were significantly lower inslah3 −/− andccc −/− mutants, but unaffected inalmt12 −/− andtmem16 −/− . We further characterised the effect ofpH andGABA by patch clamp. Strong regulation by extracellularpH was observed in the wild‐type, but not intmem16 −/− . Our results are compatible withAt TMEM 16 functioning as an anion/H+cotransporter and therefore, as a putativepH sensor.GABA presence: (1) inhibited the overall currents, an effect that is abrogated in thealmt12 −/− and (2) reduced the current inAt ALMT 12 transfectedCOS ‐7 cells, strongly suggesting the direct interaction ofGABA withAt ALMT12.At SLAH 3 andAt CCC activity is sufficient to explain the major component of extracellular anion fluxes, and unveils a possible regulatory system linkingPT growth modulation bypH ,GABA , and [Ca2+]cytthrough anionic transporters. -
Abstract Arginine synergistically inactivates enveloped viruses at a pH or temperature that does little harm to proteins, making it a desired process for therapeutic protein manufacturing. However, the mechanisms and optimal conditions for inactivation are not fully understood, and therefore, arginine viral inactivation is not used industrially. Optimal solution conditions for arginine viral inactivation found in the literature are high arginine concentrations (0.7–1 M), a time of 60 min, and a synergistic factor of high temperature (≥40°C), low pH (≤pH 4), or Tris buffer (5 mM). However, at optimal conditions full inactivation does not occur over all enveloped viruses. Enveloped viruses that are resistant to arginine often have increased protein stability or membrane stabilizing matrix proteins. Since arginine can interact with both proteins and lipids, interaction with either entity may be key to understanding the inactivation mechanism. Here, we propose three hypotheses for the mechanisms of arginine induced inactivation. Hypothesis 1 describes arginine‐induced viral inactivation through inhibition of vital protein function. Hypothesis 2 describes how arginine destabilizes the viral membrane. Hypothesis 3 describes arginine forming pores in the virus membrane, accompanied by further viral damage from the synergistic factor. Once the mechanisms of arginine viral inactivation are understood, further enhancement by the addition of functional groups, charges, or additives may allow the inactivation of all enveloped viruses in mild conditions.
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Highlight The marine diatom
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