Shamrock Capital, a Los Angeles-based investment firm specializing in media, entertainment, communications and related sectors, completed the investment in Highwire PR, a premier communications partner for technology and healthcare companies. Financial terms were not disclosed. "A growth mindset defines Highwire and a values-driven culture ensures we maintain our focus on our team as we grow. In Shamrock, we found a like-minded partner with unmatched marketing, media and communications expertise to help us build for a new era," Kathleen Gratehouse, Highwire Principal and Co-Founder.