Grounding Negative voltage through I/O pin

[Squibcakes]

Hi,

I have a -15V signal (steady state through 100k resistor) that I want to pulse to 0V every 2 secs.

Originally I wanted to use a P-MOSFET but, I need a negative gate voltage to turn it on etc. Problem is, the PIC outputs 0 to 5volts.

Instead:
Can I do away with the MOSFET all together and use an I/O pin to toggle the -15V signal.

I was planning to do this by changing the state of an I/O pin from High empedance (input pin) to low (output pin) to ground the -15V signal through the pic.

The -15V signal comes through a 100k resistor so current should be around .15ma which is well within the 25ma spec for current sinking. But is the 15V too high?

Or will this Deep fry the Chip?

Cheers
Squib