Trypsin induces Ca(2+)-activated Cl- currents in X. laevis oocytes

Area of Science:

• Cell biology
• Molecular biology
• Physiology

Background:

• Xenopus laevis oocytes are a common model for studying ion channel function.
• Calcium-activated chloride currents play roles in various cellular processes.
• The specific mechanisms triggering these currents are not fully understood.

Purpose of the Study:

• To investigate the effect of the protease trypsin on Xenopus laevis oocytes.
• To determine if trypsin can induce calcium-activated chloride currents.
• To explore the potential mechanism and specificity of this interaction.

Main Methods:

• Defolliculated, voltage-clamped Xenopus laevis oocytes were used.
• Trypsin was applied extracellularly at varying concentrations.
• Other proteases and pretreated trypsin were tested for comparison.
• Intracellular injection of trypsin was also performed.

Main Results:

• Trypsin induced dose-dependent calcium-activated chloride currents at concentrations as low as 0.1 mg/ml.
• Specificity was observed, as other proteases did not induce currents.
• Pretreated trypsin and intracellular injection failed to elicit a response.
• The current was not due to activation of the lysophosphatidic acid receptor.

Conclusions:

• A specific receptor for trypsin is likely present on the Xenopus laevis oocyte membrane.
• Trypsin-induced currents are not mediated by known calcium-mobilizing receptors.
• This finding opens new avenues for understanding oocyte signaling pathways.