What is a programmer's role in error-checking text content?

Question

As a primarily web-based programmer, a lot of my projects involve significant amounts of text content.

In my previous job, I frequently worked with a project manager notorious for his unwillingness to proof-read, or to even use basic spell-check software. I regularly corrected the text content he provided for grammar, punctuation, and spelling, as I felt that the website represented both the company and myself, and I was not willing to let his laziness contribute to a negative user experience. However, text content was limited, and was almost exclusively legal disclaimers and technical instructions related to the product.

At my current job, we have a much larger emphasis on text content. However, we also have a much higher standard of quality and proof-reading. All printed content from our department uses the AP Stylebook standards, and I believe that standard should be extended to our web-based content as well.

I fully expect that my previous problems with low-quality text content, and lack of basic proofreading, will not be repeated here. However, I have gotten into the habit of proofreading every bit of text content I publish.

I am considering studying the AP Stylebook to make sure that I know what the expected conventions are.

Is this going beyond my responsibility as a programmer? Should I be sticking to only the most basic of errors (e.g. spelling, punctuation, etc.) instead of trying to expand to AP Stylebook conventions? Or should I just leave all proofreading tasks to the people who give me the content to publish?