Substrate-recognition component of some SCF (SKP1-CUL1-F-box protein)-type E3 ubiquitin ligase complexes. Involved in endoplasmic reticulum-associated degradation pathway (ERAD) for misfolded lumenal proteins by recognizing and binding sugar chains on unfolded glycoproteins that are retrotranlocated into the cytosol and promoting their ubiquitination and subsequent degradation. Able to recognize and bind denatured glycoproteins, which are modified with not only high-mannose but also complex-type oligosaccharides. Also recognizes sulfated glycans. Also involved in DNA damage response by specifically recognizing activated CHEK1 (phosphorylated on 'Ser-345'), promoting its ubiquitination and degradation. Ubiquitination of CHEK1 is required to insure that activated CHEK1 does not accumulate as cells progress through S phase, or when replication forks encounter transient impediments during normal DNA replication.