Can you really inform a database from another database, both database take presctiption different server. and both database will vary type. eg. if i've got a DB2 database on a single server plus some records are up-to-date about this database than have to inform another DB and modify some table in on that DB(my situation it's MYSql).

Thanks ahead of time

You may create a hyperlink between databases and taking advantage of triggers - update corresponding data within the other database.

I'd investigate replication, to ascertain if mySQL could be a replication target for DB2.

Read introduction to SQL Replication.