Rosario Dawson pined so hard for the film role of Mimi, the HIV-infected strip club vixen of "Rent," that she nearly skipped the audition. It just meant so much to her that the idea of vying for the part and not getting it seemed crushing.

"I got freaked out because what if my voice broke while I was dancing because I was out of breath or something," Dawson says, sitting cross-legged on a couch in the Ritz-Carlton Hotel in Battery Park.

Why the anxiety? Because Dawson, like Mimi, hails from the Lower East Side, and she, like Mimi, lived there in an apartment without heat or electricity. Nobody expects the cast of any musical production to have firsthand knowledge of the world they are pretending to inhabit, and it's no knock on anyone else in the film that he or she is guessing at what it would be like to dwell in poverty-stricken New York in the mid-'80s. But those are Dawson's roots.

"We had a big, gaping hole in the middle of the floor when we moved in," she remembers. "Sheets of plastic on the windows. At first there was no running water, no heat, no electricity. My mother learned to be a plumber and put in all the pipes in our place."

The way Dawson describes the experience, it all sounds kind of exciting. Then again, this woman could make a tax audit sound festive. Dawson, 26, is enthusiasm incarnate and speaks in gushers, bouncing from topic to topic, with barely a pause to inhale. She smiles, flips back her short black hair every few seconds and talks, a few paragraphs at a time.

Which is what she's been doing all day. The publicity operation for "Rent" has taken over a suite and a bunch of rooms in the Ritz-Carlton and the whole scene -- a combination of walkie-talkies, sofas and finger food -- looks mildly paramilitary, like a SWAT team from the Pottery Barn. A handful of women are carefully coordinating the arrival and departure of stars and journalists.

"Seth, you copy? Go to XM in two minutes," one barks.

"Take Adam back to 1233," says another.

At 3 p.m., Dawson is in Room 909 and looks likes she's just getting warmed up.

"I don't really ever lose my voice," she says. "I'm actually lucky about that."

Whatever that mysterious quality called "it" is, this woman has by the heaps.

"When I saw the first cut of the movie," recalls "Rent" director Chris Columbus, "I remember seeing this close-up of Rosario and thinking, 'This is the birth of a new movie star.' "

Well, not exactly new. Over the past 10 years, Dawson has appeared in more than a dozen movies, starting with "Kids" in 1995, a brutal and unforgettable indie about a group of skeevy Manhattan teens, released when Dawson was 16. Since then she's turned up in "Sin City," "25th Hour," "Men in Black II," and "Josie and the Pussycats." And she's made her share of stinkers, like Oliver Stone's "Alexander" and "The Adventures of Pluto Nash," an Eddie Murphy flop.

"I was like, 'Uh, I've only been acting a few years but, and not to be obnoxious or anything, but do you really want me to say the same line in every scene?' " she says, recalling the script for "Nash." "They were like, 'Don't worry, we'll fix it all later.' The story definitely needed work."

Her screen debut went a lot better. She was recruited for "Kids" right off the street, in an urban version of a Hollywood fairy tale. At the time she was living in that squat, and her dad noticed that a camera crew was working near the apartment.

"There was a Vibe commercial being filmed on my street that day and my dad said, 'Go down there and get discovered,' " Dawson says.

She wheedled her way into a couple shots as a dancer, and during a lull in shooting she noticed two men staring at her. One was 19-year-old Harmony Korine, who wrote the screenplay for "Kids." He and director Larry Clark happened to be passing by, scouting locations.

"Harmony was like, 'Oh my God, you're exactly what we've been looking for!' I'm looking at the two of these guys and thinking, 'Yeah, right.' "

Within days, Dawson was perched on the front of her father's bicycle ("That's how we traveled back then") and the two pedaled to Clark's office at Broadway and Houston. There they read the script, the account of a violent, druggy and sexually depraved day in the life of some New York teens. There's rape, AIDS and lots of nauseating amorality.

"My parents and I read the script and it was . . . heavy," says Dawson. "My mom and dad were like, 'You can do the movie as long as you don't smoke!' "

She didn't smoke. Once the movie was made -- it was shot in four days -- she assumed it would quietly sink into oblivion. (Everyone involved was new to the movie biz, after all.) With the funds from her part, Dawson and her family took a two-week vacation to Texas to visit her father's relatives. Her mother liked the town so much, she bought a house and moved the family.

Months later, the phone rang. "I got this random call saying 'Where have you been? We can't believe you're in Texas!' "

"Kids" had been shown at Sundance and was on its way to becoming a somewhat notorious hit. Harper's Bazaar flew Dawson to New York, first-class, for a group shoot with the rest of the cast. An acting career suddenly seemed possible, and eventually she moved back into her parents' apartment, this time with roommates, and enrolled in the Lee Strasberg Theatre and Film Institute. Spike Lee cast her in his 1998 movie "He Got Game."

She lives these days in Los Angeles with her boyfriend, "Sex and the City" star Jason Lewis, and a pair of Rhodesian Ridgebacks. Relocating to the West Coast, she says, had a lot more to do with giving the dogs a back yard than it did with promoting her career.

But if she seems less than eager to call herself a Californian, she'll happily admit that Los Angeles was the scene of one of the most satisfying moments of her life. It was her second "Rent" audition for Mimi, this time in a dance studio with Chris Columbus watching. Dawson remembers being so terrified she forgot to sing and dance at the same time, pretty much required skills in a musical. When she was through, she thought she'd blown it. Columbus, though, was awed.

"We had a situation where we had six of the original cast members in the movie, so I needed to find someone who would fit into this group of people who'd done the show for 16 months," he says. "When I met her, I had no idea she could sing or dance, and at the audition she sang 'Out Tonight' and just the way she moved, and her voice, which has this fragile beauty about it."

When Dawson was finished, Columbus and his collaborators huddled briefly and then told her the good news.

"I walked out the door and I told her, 'It's yours.' "

Dawson later heard the details from her manager. Yes, she'd made some mistakes during that audition, but it didn't seem to matter.

"They told my manager, 'You know, even when she was screwing up she seemed perfect.' "

Rosario Dawson had a special affinity for her "Rent" role.Dawson in "Rent." When auditioning, she was so anxious that she forgot to sing and dance at the same time. Dawson with her beau, Jason Lewis of "Sex and the City" fame, at a Fashion Week show in New York last September.