She's known now for "Saturday Night Live" and the "Ghostbusters" revival, but once upon a time Kate McKinnon was part of a Web series called "Vag Magazine." Here's a look back at her career. (Nicki DeMarco/The Washington Post)

It’s the wink that launched a thousand GIFs.

When the trailer for the new “Ghostbusters” movie was released in March, the Internet went bananas for the Holtzmann wink. Kate McKinnon, in character as Jillian Holtzmann, whom she describes as the “joyful wacko” of the film’s foursome, pauses mid-sip from a straw to stare sternly at Kristen Wiig’s character. Then she casually winks, and a sly grin rises on her face. The Internet reacted with adoring tweets, GIFs and fan art, and an illustration is available on T-shirts, mugs and phone cases.

At a recent Los Angeles media screening of the Sony film, which premieres Friday, July 15, co-stars Wiig, Melissa McCarthy and Leslie Jones received cheers during the credits, but none as loud as those for McKinnon. It’s her first starring film role, and as one of most-beloved cast members of “Saturday Night Live,” the Emmy-nominated 32-year-old is primed for crossover success. Lorne Michaels recalls that when she auditioned for SNL, before joining the cast midseason in 2012, “I looked at her and I just went, ‘Oh. Right.’ Sometimes people arrive and they’re ready. She is an impressive talent.”

Kate McKinnon plays the gear head Jillian Holtzmann in the new version of “Ghostbusters.” (Hopper Stone/Sony Pictures Entertinament)

She is also, like her latest character, an oddball. In conversation, McKinnon alternates between intense eye contact and aimless roving gazes. “She’s kooky,” says Amanda Bearse, who directed McKinnon in her first big break, as a cast member on “The Big Gay Sketch Show,” which ran on Logo from 2006 to 2010. “It works for her. It’s not an affect. It’s playfulness.”

During an interview with McKinnon at the Four Seasons in Beverly Hills, she gently rubbed a section of velvet upholstery when forming thoughts. Halfway through the conversation, she casually pulled two sections of false hair from her coif, placed them beside her, leaned toward the microphone and said, “Let the record show that she begins to remove her hair extensions.”

It is this charm that caught the eye of “Ghostbusters” director Paul Feig. He and screenwriter Katie Dippold were halfway through the script when he invited McKinnon to discuss the role of Holtzmann, the squad’s socially awkward but unflaggingly confident gearhead. “She’s perfect,” Feig recalls thinking afterward. So he tailored the role to her, in part via an improvised interview with McKinnon in character.

“It was an hour of asking her questions about her life as Holtzmann,” Feig says. “We came up with this weird backstory: She had gone off and lived in Tibet when she was 12, and then she was living with gypsies. I’m going to put some of it on the DVD.”

From left, Chris Hemsworth, McKinnon, Leslie Jones, Kristen Wiig and Melissa McCarthy in “Ghostbusters.” (Hopper Stone/Sony Pictures Entertainment)

When Holtzmann first appears onscreen, she ignites a hand torch next her face. Later, just because she can, she smashes a guitar. Then, during elaborate paranormal combat, she wields a variety of weapons she invented herself.

McKinnon never aspired to be an action hero. “If I had my druthers, I would be a brain in a jar, with a burlap skirt around the cart I’m on — I don’t attend to my physical being much,” she explains. “But there was a sense of power once I embraced it.”

In person, she is subdued but no less powerful. During almost every talk-show appearance, McKinnon gently touches the hand or arm of the host, who invariably reacts with pleased surprise. And there’s that unremitting eye contact. When it’s pointed out, she says, “It never occurred to me,” but allows, “I like to connect with people and suss them out. There’s no better way than seeing how they react if you just bear into them.”

She approaches her SNL characters similarly. “I can’t do impressions of people I can’t relate to,” she says. “It has to come from a place of understanding and celebration.”

Among her collection are Angela Merkel, Ruth Bader Ginsburg and Keith Urban. Ellen DeGeneres once invited McKinnon onto her talk show to do the impression of her by her side and giggled throughout. McKinnon’s Justin Bieber is a Peter Pan figure who points at his briefs and says, “Yo, my pee-pee’s in there”; it is nevertheless highbrow performance art.

McKinnon on Hillary Clinton: “I can relate to pushing yourself because you want to help, and move culture toward justice.” (Dana Edelson/NBC)

But the comedian is most known for her take on Hillary Clinton as a woman who is at turns playful and stern, who means well but is desperate with ambition. “It was clear she had a way of doing Hillary that was fresh,” Michaels says.

“A lot of it comes from Kate’s feelings about her,” adds SNL writing supervisor Sarah Schneider, who pens the Clinton sketches with co-writer Chris Kelly and McKinnon. “She’s a supporter. . . . Kate is the same strong but flawed woman.”

In one sketch, Clinton mentions playing hopscotch as a child, saying: “I found it tedious. I mean, why hop when you can march” — McKinnon’s tone shifts to severe, and she stares into the camera while finishing — “straight to the White House!”

In this past season’s premiere, the real Clinton appeared alongside her doppelganger. “I felt so connected to her,” McKinnon recalls. “I can relate to pushing yourself because you want to help, and move culture toward justice.”

McKinnon grew up on Long Island watching Mel Brooks movies in a home that honored comedy. She studied theater at Columbia University and, according to Bearse, was cast in “The Big Gay Sketch Show” before graduation. Meanwhile, she embedded herself in the New York comedy scene, largely at the Upright Citizens Brigade Theatre, where she staged several solo shows of characters.

McKinnon as Clinton and Larry David as Bernie Sanders on “Saturday Night Live” on April 16. (Dana Edelson/NBC)

When McKinnon joined SNL, she became the first openly gay female cast member. Although she plays several lesbian characters, they are never statement pieces. “The fact that it is perfunctory, I owe that to Rosie O’Donnell, Ellen DeGeneres, Jane Lynch, Amanda Bearse and those who took most of the bullets,” she says.

Does the chameleonic actor grow tired of fans and friends asking for impressions when she’s at parties? “I’m never at a party, so how could they?” Mc­Kinnon jokes in reply. She is very private, with no social-media presence.

This shields her somewhat from the hate being lobbed at the “Ghostbusters” remake, which has the most down-voted trailer ever to appear on YouTube. Some naysayers are simply skeptical of remaking the beloved franchise. But most of the anger is misogynistic, in response to the female cast. “I didn’t know that people could hold those opinions of women in this year of the Earth’s existence,” she says. “You have to press on anyway.”

McKinnon at the Empire State Building's observatory as part of an event for Gilda's Club NYC, a nonprofit group founded in honor of former SNL cast member Gilda Radner that provides support for cancer patients and their families, on July 12. (Charles Sykes/Invision/AP)

McKinnon’s approach to humor is an antidote. “Comedy is a tool of togetherness,” she says. “It’s a way of putting your arm around someone, pointing at something and saying, ‘Isn’t it funny that we do that?’ It’s a way of reaching out.”

Audiences return the gesture. “She has no ego,” Schneider says of McKinnon’s resonance with viewers. “You can tell when an entertainer thinks they’re funny. When she performs, it is for the pure joy of it.”

“As an old friend of mine would say,” Michaels adds, “ ‘She doesn’t spill over.’ She’s not a forceful personality. There’s an intelligence to everything she does. And she’s really, really funny.”

Ghostbusters PG-13. At area theaters. Contains supernatural action and some crude humor. 108 minutes.