SMC2
Description
The SMC2 (structural maintenance of chromosomes 2) is a protein-coding gene located on chromosome 9.
SMC2, also known as chromosome-associated protein E (CAP-E), is a protein encoded by the SMC2 gene in humans. It belongs to the SMC protein family and is a core subunit of condensin I and II, large protein complexes involved in chromosome condensation and overall organization. Several studies have shown that SMC2 is essential for cell division and proliferation. SMC2 forms a heterodimer with SMC4 through their hinge domains. This heterodimer acts as the core of a flexible and dynamic holocomplex. The condensin complex is formed when the heterodimer interacts with various non-SMC regulatory proteins. Condensin I consists of SMC2, CAP-H, CAP-D2, and CAP-G, while condensin II consists of SMC2, CAP-H2, CAP-D3, and CAP-G2. CAP-H and CAP-H2 are classified as kleisin proteins, similar to Scc1 found in cohesin. CAP-D2, CAP-G, CAP-D3, and CAP-G2 contain structural HEAT repeats. SMC2, as part of the condensin complex, participates in transcriptional regulation by compacting replicated DNA before mitotic division via DNA supercoiling. It also functions in resolving sister chromatids before anaphase. SMC2 has been shown to interact with DNMT3B. Mutations in the SMC2 gene have been linked to various human diseases, including Cornelia de Lange syndrome (CdLS). CdLS is characterized by developmental abnormalities, cognitive impairment, and a range of physical abnormalities. A study revealed that a deletion of a portion of the long arm of chromosome 9 (9q31.1-q32) causes symptoms similar to those observed in CdLS patients. This deletion overlaps the gene encoding SMC2.
SMC2 is a key part of the condensin complex, which plays a crucial role in transforming relaxed interphase chromatin into condensed chromosomes during mitosis. This complex likely introduces positive supercoils into relaxed DNA when interacting with type I topoisomerases, and converts nicked DNA into positively knotted forms when interacting with type II topoisomerases.
SMC2 is also known as CAP-E, CAPE, SMC-2, SMC2L1.
