Scribbled homolog, also known as SCRIB, is a protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 which in humans is encoded by the SCRIB gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

.

Function

Deficiency in Scrib impairs many aspects of cell polarity and cell movement

Cell migration

Cell migration is a central process in the development and maintenance of multicellular organisms. Tissue formation during embryonic development, wound healing and immune responses all require the orchestrated movement of cells in particular directions to specific locations...

. Scrib belongs to a protein complex containing betaPIX, an exchange factor for Rac/Cdc42, and GIT1

GIT1

ARF GTPase-activating protein GIT1 is an enzyme that in humans is encoded by the GIT1 gene.GIT1 contains an ARFGAP domain, Anykrin repeats, and a GRK-interacting domain. The Arf-GAP domain, which enables it to act as a GTPase activating protein for the Arf family of GTPases, has been shown to be...

, a GTPase activating protein for ARF6

Arf6

ADP-ribosylation factor 6 is a member of the ADP ribosylation factor family of GTP-binding proteins. ARF6 has a variety of cellular functions that are frequently involved in trafficking of biological membranes and transmembrane protein cargo...

 implicated in receptor recycling and exocytosis.

Clinical significance

The PDZ domain

PDZ domain

The PDZ domain is a common structural domain of 80-90 amino-acids found in the signaling proteins of bacteria, yeast, plants, viruses and animals...

 of SCRIB binds directly to the human papillomavirus

Human papillomavirus

Human papillomavirus is a member of the papillomavirus family of viruses that is capable of infecting humans. Like all papillomaviruses, HPVs establish productive infections only in keratinocytes of the skin or mucous membranes...

 E6 protein. SCRIB is targeted for ubiquitination by a complex of E6 and UBE3A

UBE3A

Ubiquitin-protein ligase E3A also known as E6AP ubiquitin-protein ligase is an enzyme that in humans is encoded by the UBE3A gene. This enzyme is involved in targeting proteins for degradation within cells...

 and E6 induces degradation of SCRIB.

Scribble inhibits breast cancer formation and depletion of scribble promotes neoplastic growth by disrupting morphogenesis

Morphogenesis

Morphogenesis , is the biological process that causes an organism to develop its shape...

 and inhibiting cell death.

Further reading