Background
This gene is a member of the cullin family. The encoded protein forms a complex that functions as an E3 ubiquitin ligase and catalyzes the polyubiquitination of specific protein substrates in the cell. The protein interacts with a ring finger protein, and is required for the proteolysis of several regulators of DNA replication including chromatin licensing and DNA replication factor 1 and cyclin E. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008],
Function
disease:Defects in CUL4B are the cause of Cabezas X-linked mental retardation syndrome (MRXC) [MIM:300354]; also called X-linked mental retardation with short stature small testes muscle wasting and tremor. MRXC patients show delayed puberty, hypogonadism, relative macrocephaly, moderate short stature, central obesity, unprovoked aggressive outbursts, fine intention tremor, pes cavus, and abnormalities of the toes.,disease:Defects in CUL4B are the cause of X-linked mental retardation-hypotonic facies syndrome type 2 (MRXHF2) [MIM:300639]; also called Smith-Fineman-Myers syndrome type 2 or SFM2. The distinguishing manifestations of MRXHF2 are relative microcephaly, short stature, hypertelorism, macrostomia, patulous lips, difficulty in speech, micrognathia, short thumbs and little fingers with adduction, hypotonia at age less than 10 years, and later hypertonia, restlessness, and seizures
