FAITHFUL FRIENDS DIANE LANE AND ELIZABETH PERKINS HAVE KNOWN THE UPS AND DOWNS OF THE SINGLE LIFE WHILE REMAINING PALS.

Byline: Evan Henerson Staff Writer

In the romantic comedy ``Must Love Dogs,'' Elizabeth Perkins and Diane Lane play sisters. Meddling, interfering sisters who can't stay out of each other's business. In fact, the arch and wise-cracking Carol (Perkins' character) prods her newly divorced sis, Sarah (Lane), into re-entering the dating market by throwing Sarah's profile onto an Internet dating service.

Interpersonal mayhem ensues, with Sarah experiencing a series of appalling first dates before two more suitable candidates (played by John Cusack and Dermot Mulroney) enter the picture. Followed by dogs.

While character traits may differ and there are no blood ties between the two women, the two actresses say there are almost as close in real life as Carol and Sarah. Friends for more than 13 years, Perkins, 44, and Lane 40, first shared the screen in ``Indian Summer'' (1993) and, over the years, have spent more than a few evenings at each other's homes while both were single mothers raising daughters in L.A.

Think ``Dogs' '' hapless Sarah has it rough with all those goofy dates? Try testing the waters again as a divorced celebrity at a time when there was no perfectmatch.com to help things along.

Not that either Lane (a future Oscar nominee for ``Unfaithful'') or Perkins (the former Wilma Flintstone) could easily specify preferences and dislikes on an electronic matchmaking site. Or that either one was even ready to do so when their friendship was blossoming.

``Neither of us really wanted to date,'' recalls Perkins. ``So it was just easier for us to get together and go to a restaurant or go to a park, go to a movie. We spent a lot of time - two single women with their children going out to movies and discussing, 'Well, maybe we should start going out on dates.' ''

``It's nice because she's always a little bit ahead of me in experience, in motherhood and work,'' Lane says of Perkins. ``So it's nice to have somebody I can consult with. We have a lot of similar experience, and there's an endless supply of banter.''

As things turned out, comfort and familiarity spread throughout the cast, in large part because Perkins - a late addition to ``Must Love Dogs'' - had long friendships with practically everybody in the principal cast, from Lane to Mulroney to Stockard Channing as well as with writer/director Gary David Goldberg.

``My nickname among my group of friends is 'Mother,' and I tend to take care of everybody,'' Perkins says. ``Making this movie was sort of like an old-home week.''

Perkins and Lane - who will appear together again in the upcoming ``Fierce People'' - still banter, albeit over different subjects. The friends who once were married and then single mothers together now have second marriages and stepchildren. Perkins took the replunge first in 2000, marrying cinematographer Julio Macata, who she met while filming the remake of ``Miracle on 34th Street.''

Lane would wed actor Josh Brolin a few years later. In the interim, however, how did she take the news of her single-mom comrade in arms leaving the market?

After some name-calling, says Perkins, laughing, ``Then she'd say, 'Well I guess I can't come over tonight because I guess he's coming over.' But, actually, she was very supportive, and she and my husband are very good friends. Both the families are very close.''

Carol is one of ``Must Love Dogs' '' few happily partnered characters. Pretty much everyone else we encounter is looking for love, including boat builder Jake (Cusack), preschool dad Bob (Mulroney) and even Sarah and Carol's recently widowed father, Bill (Christopher Plummer) who also takes to the Internet and meets with considerably more success than his daughter.

The film, which opens Friday, is set in L.A., not an easy city in which to meaningfully hook up. Perkins, who was divorced from actor Terry Kinney, recalls L.A. as being ``probably one of the loneliest places to be raising a child alone.''

``You put your daughter to bed at 7:30, and there you are,'' she says. ``Once you get over the relationship you left, it's very difficult to move on from that point because you know whoever's going to enter into your life, it's not just you anymore. It's also your child.''

For obvious reasons, celebrities aren't typically the ones people find posting profiles on Web dating sites, meaning they have to meet people the old-fashioned way. Although she's never done it, Perkins says it's not unheard of for an actor with an interest in another actor to set up an encounter via their respective publicists.

If you want to find someone outside the industry, however, that's when things can get tricky, according to Perkins.

``You don't necessarily always want to be with someone who works in your business,'' she says. ``It takes a certain kind of couple that are both actors to be able to make it, and it takes a certain kind of ego and lack of competition and ability to really sustain a relationship while you're spending a lot of time apart. I'm with a cinematographer. He's very stable, and I'm highly neurotic - so it works.''

Like director Goldberg (``Family Ties,'' ``Dad'') Lane collected people's stories in conducting research for Sarah's lonely-heart odyssey. The story is adapted from the novel by Claire Cook, which has Sarah's sister placing a personal ad, not an online profile.

``I've heard that you can sort of loiter in bookstores and people see what you're reading. That's a pickup place now instead of bars,'' says Lane, who was formerly married to actor Christopher Lambert. ``Where else? The doggie park as well. You can sort of ambulate around and pretend you're not scouring. The jokes are there in our script, and they're very accurate. You can go to Home Depot and pretend to be a damsel in distress. It's very funny what people do to avoid being overly intentional.''

And the Internet?

``Look, it's so interesting, because being a mom of a daughter - forget about it,'' says Lane. ``I'm so hyper mama-bear protective: 'In no way is it ever all right to meet anybody you've (only) ever met online! Period! End of story. Close chapter, end the book.' But in my prickly, paranoid way, I'd say, 'Well don't they kind of prescreen people at these agencies?' So I like the fact these services exist, and I think if you're meeting someone randomly outside the protection of the umbrella, you know you can't say you weren't warned.''

Perkins and Lane will have little screen time together in Griffin Dunne's ``Fierce People.'' The two women play the mothers of boys who befriend each other and eventually become enemies.

The two women remain close, as do their daughters, who are 14 and 11 and tight friends.

Actually, that's not quite right.

``They're not really friends,'' says Perkins. ``They're sisters.''

Evan Henerson, [phone]

evan.henerson(at)dailynews.com

PET PROJECTS

Those adorable pooches. How we love them! How they figure in our lives when we're in love with someone of the two-legged variety.

Although they're not always the fuzzy Cupids we'd like them to be, dogs often find their cold-nosed way into romantic comedies. A few recent examples:

``Dog Park'' (1998): The entire dating scene in Bruce McCulloch's comedy revolves around dog parks. Luke Wilson and Natasha Henstridge star.

``The Truth About Cats and Dogs'' (1996): Radio vet Abby (Janeane Garofalo) and photographer Brian (Ben Chaplin) meet when she talks him down from an encounter with a dog on roller skates.

``There's Something About Mary'' (1998): OK, a bit twisted as romantic comedies go, but who can forget Ben Stiller's encounters with Lin Shaye and Cameron Diaz's unfortunate pooch.

``You've Got Mail'' (1998): Tom Hanks, Meg Ryan and, in the final scene, a mongrel who plays a key part.

``As Good as It Gets'' (1997): Greg Kinnear's pooch, Verdell, nearly steals the show from Jack Nicholson.

- E.H.

CAPTION(S):

6 photos, box

Photo:

(1 -- cover -- color) It's personal

For friends Diane Lane and Elizabeth Perkins, `Must Love Dogs' hits close to home

(2) Dogs are good listeners, and Sarah (Diane Lane) looks like she could use a furry, nonjudgmental shoulder to cry on as she re-enters the dating world.

(3) Elizabeth Perkins, left, director Gary David Goldberg and Diane Lane on the set of ``Must Love Dogs.''

(4) John Cusack and Diane Lane hit it off.

(5) Janeane Garofalo and friend in ``The Truth About Cats and Dogs.''

(6) Jack Nicholson and Verdell in ``As Good as It Gets.''

Box:

PET PROJECTS (see text)