Moving sequences to another schema

I'm still playing around with the ALTER OBJECT SET SCHEMA stuff. I managed 
to alter indexes and constraints as well for tables, but with SERIAL 
sequences there is one little problem:

When altering a sequence created by a SERIAL column type (i do this by 
examining pg_depend to avoid moving any other sequences that are 
'foreign'), i need to recreate the default expression for the SERIAL column 
(stored in pg_attrdef.adbin). Is there an API to do that, or do i have to 
recreate the executable expression tree from scratch? Or am i missing 
something completely...

TIA

-- 

 Bernd