You can access your translations from the Locale relationship:
GET
/locales/{locale_id}/translations.xml
=> Returns a list of translations
GET
/locales/{locale_id}/translations/{translation_id}.xml
=> Returns a translation
PUT
/locales/{locale_id}/translations/{translation_id}.xml
=> Supply with attribute params, updates the translation
POST
/locales/{locale_id}/translations
=> Supply with attribute params, creates a translation
DELETE
/locales/{locale_id}/translations/{translation_id}.xml
=> Deletes the translation
And you can access them from they Key relationship:
GET
/keys/{key_id}/translations.xml
=> Returns a list of translations
GET
/keys/{key_id}/translations/{translation_id}.xml
=> Returns a translation
PUT
/keys/{key_id}/translations/{translation_id}.xml
=> Supply with attribute params, updates the translation
POST
/keys/{key_id}/translations
=> Supply with attribute params, creates a translation
DELETE
/keys/{key_id}/translations/{translation_id}.xml
=> Deletes the translation