I'm going to have to disagree with 411. According to Google's Search Raters Guidelines document that was released last year, they're taking into account your site/company's overall reputation. This means they're not only looking at Google Reviews, but third party review/reputation sites as well. It's part of their initiative to improve the quality of results. It doesn't matter how many links you have or how good your site structure and on-page SEO is if the service or product you provide is terrible and gets bad reviews everywhere you look.
For a summary of what's in these guidelines, check out this summary: https://moz.com/blog/google-search-quality-raters-guidelines. The whole guidelines document is worth reading, but be sure to check out the Reputation section and the 5 clues of what makes a page low quality in this post.