assigning a user to an account

[JohnBlack]

Is it possible to assign a user to an account and set it up so that only he can add data to that account?
I'm in an environment where there are different teams working on all sorts of projects.
And it would be very convenient if (for example) user "team1" logs in, he only sees the accounts and the projects assigned to team1. And that team1 (and the admin ofcourse) is the only user that can change and add data to those accounts.

[JohnBlack]

Anybody got an idea on how to achieve this ?