SPAG9
SPAG9 (sperm associated antigen 9) is a JIP-family scaffold protein that organises components of the MAPK cascade to mediate JNK signalling. It is also known as JIP4, JLP, PIG6, CT89 and C-Jun-amino-terminal kinase-interacting protein 4. Browse Assay Genie's current range of SPAG9 research reagents below, or read on for the biology behind the target.
SPAG9 belongs to the JNK-interacting protein (JIP) group of scaffold proteins. These proteins selectively mediate JNK signalling by aggregating specific components of the MAPK cascade into a functional JNK signalling module. According to the NCBI Gene summary, the encoded protein structurally organises mitogen-activated protein kinases and mediates c-Jun N-terminal kinase signalling.
Beyond kinase scaffolding, SPAG9 regulates lysosomal positioning. It acts as an adapter that links PIP4P1-positive lysosomes to the dynein-dynactin complex. It also assists the selective functionality of PIKFYVE in microtubule-based endosome-to-TGN trafficking, and it binds kinesin-1, so it may contribute to microtubule-based membrane transport. UniProt records the protein in the cytoplasm, the perinuclear region, the lysosome membrane and the acrosome of secretory vesicles. The SPAG9 gene has a mouse ortholog, Spag9, and alternate splicing gives multiple transcript variants.
The SPAG9 gene encodes a member of the cancer testis antigen gene family, which is reflected in the alias CT89 and in the name sperm associated antigen 9. The protein may play a role in tumour growth and development. The many aliases in the literature, including HSS, SYD1, KIAA0516, JLP, PHET, HLC4, JIP4 and PIG6, reflect its independent discovery in different contexts. Researchers studying SPAG9 should check which name a given paper uses.
SPAG9 is a JIP scaffold that assembles MAPK cascade components into a JNK signalling module, making it a focus for studies of pathway specificity.
SPAG9 links PIP4P1-positive lysosomes to the dynein-dynactin complex and assists PIKFYVE in endosome-to-TGN trafficking.
As a cancer testis antigen family member that may play a role in tumour growth and development, SPAG9 is studied in oncology.
SPAG9 binds kinesin-1 and may be involved in microtubule-based membrane transport, relevant to motor protein and cargo studies.
SPAG9 is a scaffold protein of the JIP family that aggregates MAPK cascade components to mediate JNK signalling. It also regulates lysosomal positioning by linking PIP4P1-positive lysosomes to the dynein-dynactin complex, and it assists PIKFYVE in endosome-to-TGN trafficking.
SPAG9 is also called JIP4, JIP-4, JLP, PIG6, CT89, HSS, SYD1, PHET, HLC4 and KIAA0516. UniProt lists the protein name as C-Jun-amino-terminal kinase-interacting protein 4. Alternate splicing produces multiple transcript variants.
SPAG9 is a member of the cancer testis antigen gene family and may play a role in tumour growth and development. A mouse ortholog, Spag9, exists. Check the datasheet of any product for its validated reactivity.
Other sperm associated antigen family members with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt O60271; product specifications from Assay Genie datasheets.