Implement SPATIAL_REF_SYS table (from the OGC Simple Features spec). This table stores metadata about different coordinate systems and how to tranform between them. See here and here for details.

CREATE TABLE SPATIAL_REF_SYS
(
    SRID      INTEGER   NOT NULL PRIMARY KEY,
    AUTH_NAME CHARACTER VARYING(256),
    AUTH_SRID INTEGER,
    SRTEXT    CHARACTER VARYING(2048)
)

https://raw.githubusercontent.com/postgis/postgis/svn-trunk/spatial_ref_sys.sql

This would be used in conjunction with the GeoTools referencing module or Proj4J to transform between coordinate systems in Teiid (ST_Transform function).